SSD as bootdisk instead of SD

Hi, i have a bananapi A20 with the image 2019-09-18-debian-10-buster-mate-desktop-grub-preview-bpi-m1-sd-emmc.img. on that a20 i have installed Octoprint. It boots from SD right now. It works fine incuding the webcam. Now i want to change it to SSD. I tried several time but it doesnt work. I also find a lot of Guides, but it doesnt . Sometimes at the end they want to chandge the uEnv.txt ( i dont have ione) then i should change the bood.cmd. I have one, but not in this folder . I change it but it boots from Sd again. df -h shows only the sd card. Can somebody help me with my problem? I am an absolute beginner aboout Linux.



hi, no ideas?

Regards Alero