tax_query not working for taxonomy slug

I can’t comment so I have to provide an answer which I don’t have a full answer. If I were you I would print_r($slug) and see what it gives you. The $slug variable is most likely not in a format that ‘terms’ can accept.

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