How to convert all project files from "regular file" encoding to cp1251?

Question

bash

I write this to find out the encoding of the file

BRAIN:method_pay fast$ enca method_pay.php -L russian
Unrecognized encoding

And to convert I write this
enconv -L russian -x cp1251 method_pay.php
And it still remains Unrecognized encoding
How to convert all project files from the "regular file" encoding to cp1251 through the terminal?