HTB ACADEMY - Skills Assessment : SQL Injection Fundamentals

Hello everyone and good evening,
I am stuck on the last challenge of sql injection fundamentals.
I crawled the target web and found some dirs, tried to bypass with mysql with PAYLOADALLTHETHINGS repo… no luck… where can i begin? Is there another way to bypass authentication?

solved !!! :slight_smile: pm me if you are stuck

how to do this…
Login as the user with the id 5 to get the flag.
any clue please…