How to redirect the frontend of a WordPress site (only)?

Use below rule,

RewriteEngine On

# excluding www
RewriteCond %{HTTP_HOST} !^www
RewriteCond %{HTTP_HOST} ^blog

# excluding wp-admin
RewriteCond %{REQUEST_URI} !^wp-admin
RewriteRule ^ https://www.example.com/%1

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