Step 1. Log into Windows Plesk


Step 2. Click on Backup & Restore

Step 3. Click on Backup

Step 4. You can choose Full  and Click the necessary boxes then click on OK ( You can decide What Content you wish to Backup, and Whether its to be a full or incremental backup )

Step 5. You can then Schedule your backup How often you would like to by following this Link :

How to schedule backups in Windows Plesk