Your Helm Personal Server is designed to automatically backup every 24 hours.
To check the backup status of your Helm, go to Settings > Helm > Backup Status. The Last Successful backup will be reported there.
Backups can be started at any point by going to this same page and tapping "Start Backup Now." A notification will confirm that a backup has been initiated and the status will expand to include a "Last Attempted" line.
If your Helm Personal Server ever fails to successfully backup, the dashboard in the Helm App displays a notification informing you. To initiate a backup, go to Settings > Helm > Backup Status.