When you open the url (https://knightsquad.org/KCTF-2022?cypto=03MTJ3M2NjcfBDdfR2Mz42X1BTefN3MNFDdz0EMTtnRUN0S) you will see 03MTJ3M2NjcfBDdfR2Mz42X1BTefN3MNFDdz0EMTtnRUN0S at the end. Reverse the text 03MTJ3M2NjcfBDdfR2Mz42X1BTefN3MNFDdz0EMTtnRUN0S you will get S0NURntTME0zdDFNM3NfeTB1X24zM2RfdDBfcjN2M3JTM30 It's base 64 encoded decode it to get flag

Original writeup (https://knightsquad.org/KCTF-2022?cypto=03MTJ3M2NjcfBDdfR2Mz42X1BTefN3MNFDdz0EMTtnRUN0S).