If TWRP doesn’t support encryption on your device, just hit “Cancel” at the password prompt to proceed to work with the other partitions.
This doesn’t help with backing up the data partition, of course, and TWRP wouldn’t backup Internal Storage anyway … https://twrp.me/faq/backupexclusions.html.
But if it is not TWRP. Which tool shall I usw to backup all my changes (documents and photos) on a daily Basis.
I dont want ti share my life with Googles. so the Fiofle services for this arent installed.
It should be. Installing an OS doesn’t concern the data partition (not at this point at least, an OS might complain about the state of the data partition and demand a factory reset once it is installed, but this is a different matter then).
What’s the error message?
Did you skip the password prompt and start ADB Sideload in TWRP before running the command?
Edit: On second thought, you need a backup first, so leave that for later .
As far as I’ve seen there is no general answer fitting every device, situation and user preference. A forum search might help you find something you might like to do.
You better completely remove your password, this may “uncrypt” your data partition.
Try the method proposed here : [HOWTO] Backup and Restore Data on Android Devices (chapter 2/, second dot about Secure Boot). You may not have Secure Boot, but the method is still valid.