So the challenge was all about messaging the bot with (what they say 4 characters. But the bot didn't replied to me for any of my input. So I have tried to see what is all about with the given Flag: **RRQZQC1CIXDFPIXWVYLQ2**.
I have tried **https://www.dcode.fr/cipher-identifier** and it gave 3 star with *Affine Cipher*.
It has Automatic brute force decryption and gave:A=1,B=23	UUTCTF1FLAGISLAZYBOT2which was the flag**UUTCTF{FLAGISLAZYBOT}**So the whole task wasn't even about the bot. Chall rating 0/5