Can't find the right string in functions-enfold.php

Hi, I need to debug, I follow your instruction to search this string:
if(isset($avia_config[‘use_child_theme_functions_only’])) return;

after that, I have to paste the code:
//set builder mode to debug
add_action(‘avia_builder_mode’, “builder_set_debug”);
function builder_set_debug()
{
return “debug”;
}

but the problem is I can’t find that string

Thank