Category shows only top level child categories

'depth' is not a parameter for the function get_categories();
to get only direct child categories, try working with 'parent' instead of 'child_of'

https://developer.wordpress.org/reference/functions/get_categories/
https://developer.wordpress.org/reference/functions/get_terms/

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)