This is an easy OSINT challenge which revolves around using the Wayback Machine.
In the challenge description and title it alludes to data not being erased from the internet which usually incidates using the Wayback Machine to see what was there in the first place. Additionally, Ducky, was using something called "CTF clock" which alludes to "CTFTime".
If you look up, our CTFTime event link (https://ctftime.org/event/1312) in the Wayback Machine (https://web.archive.org/web/*/http://ctftime.org/event/1312). You will see there was a snapshot taken on the 14 of March that says Ok, ok — here is your flag: a5abef5222adc680a453607384bcb4d2.
You take this flag from and put it inside the DUCTF flag format and you have the flag!
Flag: DUCTF{a5abef5222adc680a453607384bcb4d2}