The installation instructions at Install /e/ on a Gigaset GS290 - “GS290” seem to be outdated.
The ‘recovery.img’ image link should always point to the latest stable image. (Which is at the time of writing this https://images.ecloud.global/stable/GS290/recovery-e-0.18-q-20210827132306-stable-GS290.img). The OTA later on could fail otherwise (Please refer to here if you want to read more about that issue.).
Kind regards
Chris