If you are logged into the administration interface of the MySQL database with the correct MySQL user, you can import a database backup file of the relevant database by following these steps:
Manually restoring a MySQL database
4. Select import source
If you want to restore a database from an SQL file, click «Select file» in the section «File to import» to navigate to the file stored on your device.
The procedure for restoring an SQL file is described here.
Creating a manual MySQL database backup