Thanks for reaching out Mpv2566,
It sounds like you're having trouble backing up with iCloud, we can help.
A good place to start is with these steps to see How to back up your iPhone or iPad with iCloud:
Automatically back up with iCloud Backup
1. Make sure that iCloud Backup is turned on in Settings > [your name] > iCloud > iCloud Backup.
2. Connect your device to a power source.
3. Connect your device to a Wi-Fi network.
4. Make sure that your device's screen is locked.
5. If you get an alert says that you don't have enough iCloud storage space to complete the backup, follow the onscreen steps to buy more storage.
If you continue having difficulty, you may want to try backing up using a Mac or Windows PC instead.
Hope that helps.
Take care.