From the same article you posted, but edited by me:
Access denied for user
You can see an error message which looks like Access denied for user 'epiz_12345678'@'192.168.0.*' (using password: YES). This message means that the user was able to connect, but does not have access to the provided database name.
This could mean one of two things.
This generally means that the database name is not correct. If you entered the database name my_database when creating the database, the full database name looks like epiz_12345678_my_database. You can find the database name in the MySQL Databases menu as well.
It could also mean that your database password is incorrect. The database password is the same as your hosting account password (which is generally different from your client area password!). You can find your hosting account password by logging in to your client area, selecting the hosting account, scrolling down to “Account Details” and clicking on “Show/Hide” to show the password.
You can try to do it. If it works, then you will thank me. If not, recreate it with another name and update the database details to use the new database name.