diff --git a/lib/l10n/app_en.arb b/lib/l10n/app_en.arb
index 33108f7d..a8140823 100644
--- a/lib/l10n/app_en.arb
+++ b/lib/l10n/app_en.arb
@@ -53,6 +53,16 @@
   "@invalidUsername": {
     "description": "Error message when the user enters an invalid username"
   },
+  "apitoken": "API Key",
+  "@apitoken": {},
+  "invalidApitoken": "Please enter a valid API key",
+  "@invalidApitoken": {
+    "description": "Error message when the user enters an invalid API key"
+  },
+  "apitokenValidChars": "A API key may only contain valid hex, a-f and 0-9 and should be 40 characters long",
+  "@apitokenValidChars": {
+    "description": "Error message when the user tries to input a API key with forbidden characters"
+  },
   "customServerUrl": "URL of the wger instance",
   "@customServerUrl": {
     "description": "Label in the form where the users can enter their own wger instance"
diff --git a/lib/providers/auth.dart b/lib/providers/auth.dart
index 1bfbdca1..1d8977f1 100644
--- a/lib/providers/auth.dart
+++ b/lib/providers/auth.dart
@@ -48,6 +48,7 @@ class AuthProvider with ChangeNotifier {
   static const SERVER_VERSION_URL = 'version';
   static const REGISTRATION_URL = 'register';
   static const LOGIN_URL = 'login';
+  static const TEST_URL = 'userprofile';
 
   late http.Client client;
 
@@ -129,7 +130,7 @@ class AuthProvider with ChangeNotifier {
       throw WgerHttpException(response.body);
     }
 
-    return login(username, password, serverUrl);
+    return login(username, password, serverUrl, null);
   }
 
   /// Authenticates a user
@@ -137,21 +138,43 @@ class AuthProvider with ChangeNotifier {
     String username,
     String password,
     String serverUrl,
+    String? apiToken,
   ) async {
     await logout(shouldNotify: false);
 
-    final response = await client.post(
-      makeUri(serverUrl, LOGIN_URL),
-      headers: {
-        HttpHeaders.contentTypeHeader: 'application/json; charset=UTF-8',
-        HttpHeaders.userAgentHeader: getAppNameHeader(),
-      },
-      body: json.encode({'username': username, 'password': password}),
-    );
-    final responseData = json.decode(response.body);
-
-    if (response.statusCode >= 400) {
-      throw WgerHttpException(response.body);
+    String token;
+
+    if (apiToken != null) {
+      final response = await client.get(
+        makeUri(serverUrl, TEST_URL),
+        headers: {
+          HttpHeaders.contentTypeHeader: 'application/json; charset=UTF-8',
+          HttpHeaders.userAgentHeader: getAppNameHeader(),
+          HttpHeaders.authorizationHeader: 'Token ${apiToken}',
+        },
+      );
+
+      if (response.statusCode != 200) {
+        throw WgerHttpException(response.body);
+      }
+
+      token = apiToken;
+    } else {
+      final response = await client.post(
+        makeUri(serverUrl, LOGIN_URL),
+        headers: {
+          HttpHeaders.contentTypeHeader: 'application/json; charset=UTF-8',
+          HttpHeaders.userAgentHeader: getAppNameHeader(),
+        },
+        body: json.encode({'username': username, 'password': password}),
+      );
+      final responseData = json.decode(response.body);
+
+      if (response.statusCode >= 400) {
+        throw WgerHttpException(response.body);
+      }
+
+      token = responseData['token'];
     }
 
     await initVersions(serverUrl);
@@ -162,7 +185,6 @@ class AuthProvider with ChangeNotifier {
     }
 
     // Log user in
-    token = responseData['token'];
     notifyListeners();
 
     // store login data in shared preferences
diff --git a/lib/screens/auth_screen.dart b/lib/screens/auth_screen.dart
index aa61caba..b0079fb8 100644
--- a/lib/screens/auth_screen.dart
+++ b/lib/screens/auth_screen.dart
@@ -120,6 +120,7 @@ class _AuthCardState extends State<AuthCard> {
     'email': '',
     'password': '',
     'serverUrl': '',
+    'apitoken': '',
   };
   var _isLoading = false;
   final _usernameController = TextEditingController();
@@ -129,6 +130,7 @@ class _AuthCardState extends State<AuthCard> {
   final _serverUrlController = TextEditingController(
     text: kDebugMode ? DEFAULT_SERVER_TEST : DEFAULT_SERVER_PROD,
   );
+  final _apitokenController = TextEditingController();
 
   @override
   void dispose() {
@@ -137,6 +139,7 @@ class _AuthCardState extends State<AuthCard> {
     _password2Controller.dispose();
     _emailController.dispose();
     _serverUrlController.dispose();
+    _apitokenController.dispose();
     super.dispose();
   }
 
@@ -162,6 +165,7 @@ class _AuthCardState extends State<AuthCard> {
   void _resetTextfields() {
     _usernameController.clear();
     _passwordController.clear();
+    _apitokenController.clear();
   }
 
   void _submit(BuildContext context) async {
@@ -182,6 +186,7 @@ class _AuthCardState extends State<AuthCard> {
           _authData['username']!,
           _authData['password']!,
           _authData['serverUrl']!,
+          _authData['apitoken']!,
         );
 
         // Register new user
@@ -271,6 +276,10 @@ class _AuthCardState extends State<AuthCard> {
                     textInputAction: TextInputAction.next,
                     keyboardType: TextInputType.emailAddress,
                     validator: (value) {
+                      if(!_apitokenController.text.isEmpty) {
+                          return null;
+                      }
+
                       if (value == null || value.isEmpty) {
                         return AppLocalizations.of(context).invalidUsername;
                       }
@@ -329,6 +338,10 @@ class _AuthCardState extends State<AuthCard> {
                       controller: _passwordController,
                       textInputAction: TextInputAction.next,
                       validator: (value) {
+                        if(!_apitokenController.text.isEmpty) {
+                            return null;
+                        }
+
                         if (value!.isEmpty || value.length < 8) {
                           return AppLocalizations.of(context).passwordTooShort;
                         }
@@ -367,6 +380,58 @@ class _AuthCardState extends State<AuthCard> {
                             : null,
                       );
                     }),
+                  if (_authMode != AuthMode.Signup)
+                    Row(children: <Widget>[
+                      Expanded(
+                        child: new Container(
+                            margin: const EdgeInsets.only(left: 10.0, right: 20.0),
+                            child: Divider(
+                              color: Colors.black,
+                              height: 36,
+                            )),
+                      ),
+                      Text("OR"),
+                      Expanded(
+                        child: new Container(
+                            margin: const EdgeInsets.only(left: 20.0, right: 10.0),
+                            child: Divider(
+                              color: Colors.black,
+                              height: 36,
+                            )),
+                      ),
+                    ]),
+                  if (_authMode != AuthMode.Signup)
+                    TextFormField(
+                      key: const Key('inputApitoken'),
+                      decoration: InputDecoration(
+                        labelText: AppLocalizations.of(context).apitoken,
+                        errorMaxLines: 2,
+                        prefixIcon: const Icon(Icons.password),
+                      ),
+                      // autofillHints: const [AutofillHints.apitoken],
+                      controller: _apitokenController,
+                      textInputAction: TextInputAction.next,
+                      keyboardType: TextInputType.emailAddress,
+                      validator: (value) {
+                        if(!_usernameController.text.isEmpty || !_passwordController.text.isEmpty) {
+                            return null;
+                        }
+                        if (value == null || value.isEmpty) {
+                          return AppLocalizations.of(context).invalidApitoken;
+                        }
+                        if (!RegExp(r'^[a-f0-9]{40}$').hasMatch(value)) {
+                          return AppLocalizations.of(context).apitokenValidChars;
+                        }
+
+                        return null;
+                      },
+                      inputFormatters: [
+                        FilteringTextInputFormatter.deny(RegExp(r'\s\b|\b\s')),
+                      ],
+                      onSaved: (value) {
+                        _authData['apitoken'] = value!;
+                      },
+                    ),
                   // Off-stage widgets are kept in the tree, otherwise the server URL
                   // would not be saved to _authData
                   Offstage(