You tapped Start Backup on Android and nothing happens—no progress, no error? 1SE Cloud backup needs a Pro subscription. If you have one and the backup still won't start or finish, these three steps fix it in most cases. Try them in order.
Sign out and back in
Tap the Settings icon > Account > Sign Out, then sign back in with the same account. Go to Profile > gear icon > Backup and Restore and tap Start Backup.
Force-quit and reopen the app
Swipe 1SE away from your recent apps, reopen it, and tap Start Backup once more.
Let 1SE work in the background
Go to your phone's Settings > Apps > 1SE, open App battery usage, and turn on Allow background usage. Some phones call this setting Unrestricted instead. Battery optimization can pause the backup the moment you leave the app. Start the backup again, keep the phone on Wi-Fi, and leave it powered on until it says it's complete.
If the backup still won't finish after all three, open Settings > Contact Support in the app and tell us.