I have to insert a row into functions.php
The row is:
I tried to create a new functions.php in the child folder that I'm using for the language translation, but maybe this is wrong because I see the row in the post and often I see only a white page.
So I inserted the row as last row of the true functions.php, and it is ok, but with next update I'll surely lose the change.
What I have to do?