Error converting tabs to spaces

Good night, someone could help me with this mistake.

ERRORS: The following files contain tabs. Change them to spaces

I’ve been trying to solve it all day but the truth is that the error is not very specific since it doesn’t say in which line of the code the error is

Thank you very much. I’ll use your solution and let you know if it works for me.

Brother thank you very much if your solution worked for me thank you