Hey there.
To upgrade to iode 7.x version, you will need to first update your Updater app, as per this announcement: iodéOS 7 is Now Officially Available! - iodé
Link for the updater APK: https://gitlab.iode.tech/ota/ota/-/blob/master/fixes/Updater-v6-to-v7.apk (might be easiest to download on your PC and transfer it to your BraX3 via USB).
Once you update your Updater, you should be able to download and install iode 7.1
If the download gives you an error, you can download the build manually from here: brax3/iode-7.1-20251227-brax3-ota.zip · master · ota / release · GitLab . Once the file is transfered to your phone, you can use the Local Update feature of the updater (top right corner when you open the app).