Is it good practice to use REST API in wp-admin plugin page? [closed]

You can and should totally do this in my opinion. Especially if you have a RESTful case. I personally only use admin-ajax for very simple things to almost no more.

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