Thnaks tcecyk
I’m aware that TWRP is the way to go for a Backup. The problen is, on the Gigaset GS290 Smartphones which my Client bought via /e/-shop is eRecovery (eRecovery Testing!) installed instead of TWRP . As far as I know there is no offical TWRP for GS290. And I see no obvious Backup and Restore functionality in eRecovery (yet?).
I want to Backup a system inclusive settings, apps etc, to wich I can reset the phones anytime. But how can I do that with eRecover instead of TWRP?