Pagination not working in custom page, only working in post page

Remove the following line from your $args array:

'post_type'=> 'post',

Or change it to:

'post_type'=> 'any',

This is only running the query on posts and will not work on pages.
The following explains this in more detail: https://wordpress.org/support/article/post-types/

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