EDL backup of my shift6mq phone

Preface : My shift6mq shift-phone is back. It was broken , so to fix it, I had send it to shift to flash my phone. EDL backup Off course my goal is to install postmarketOS again. But first, let’s try to make a backup, so when things break again I can hopefully fix it myself. How? I downloaded the live DVD iso at https://github.com/bkerler/edl and booted a PC with it. By pressing volume up and…