Can someone help me I've been trying to fix this for many hours now. I'm trying to delete something from database but my work is not working. I changed my username and password to "-" so i dont share

Can someone help me I've been trying to fix this for many hours now. I'm trying to delete something from database but my work is not working.

I changed my username and password to "-" so i dont share my account.

Here's what my page look like right now:

Admin.php

 Id

 Category Name

 Delete