Hi there, you bruteforced and got the correct otp but next time you tried it didn't work because:

- You can only enter OTP one time and get response with cookies

which means you already have achieved that when you bruteforced and found the correct otp so when you enter it next time it doesn't work because the code has already been used

What could have been done here is:

- after u get correct OTP by bruteforcing, check its response and copy it in notepad

- enter any wrong otp and intercept request and its response

- replace the response with the response you copied to notepad

and it should work ;)