How to redirect old permalinks to ones generated by [WP-Hashed-ID] plugin?

Depending on the number of posts that you have, you might just use a plugin like Redirection. It’s easy and straightforward, if time consuming.

Good luck!

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