WordPress multisite installation subdomains not working properly

Switching from sub directories to sub domains is not easy. Start by looking at https://wordpress.org/support/article/multisite-network-administration/#switching-network-types, besides that, you might also need to run search + replace queries on the database to update the URLs on the content, and re-save the permalink structure.

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