Samsung S9, v3.0.4 official, /e/ Recovery loop, Signal backup

There’s a lot of info in the threads. Here’s what I did so far.

According to https://community.e.foundation/t/tuto-installer-adb-et-fastboot-sur-votre-pc-avec-linux/54357:
On my pc:

  • I downloaded latest version of SDK Platform-Tools for Linux (I’m running Ubuntu 24.04.2)
  • I ran “mkdir ~/android-adb-fastboot” (where ~ is “/home/user/”)
  • I ran “mv ~/Téléchargements/platform-tools-latest-linux.zip ~/android-adb-fastboot”
  • I ran “unzip ~/android-adb-fastboot/platform-tools-latest-linux.zip -d ~/android-adb-fastboot”
  • I plugged my phone to my PC using USB cable

On my phone:

  • From Recovery 2-item menu, I pressed back arrow to get to Recovery 4-item menu
  • I pressed Advanced
  • I pressed Enable ADB

On my PC:

  • I ran “sudo apt install adb”
  • I ran “adb shell”

From ADB shell:

I read:

I’m still confused about which command lines to type in order to locate and delete excessively large Signal backup files.

Could you please clarify?