how to turn off two factor autenticacion

I'm assuming that you are referring to this authentication type for your Apple ID ... correct? If so, basically, you can't. Apple only offered the ability to do this within a short time window (2 weeks) after enabling it in the first place.

Are you having any specific issue w/ 2FA with which we might assist?

This article gives a very good overview:

https://support.apple.com/en-us/HT204915

In addition to what Teserax correctly suggests, if you were able to turn of Two Factor Authentication, you'd find many Apple services rendered inoperable on your phone.

Everything you wanted to know about two factor authentication, but were afraid to ask→Stay safe with Two Factor Authentication … - Apple Community

Woo hoo !!!

Thanks for suggesting it!