Okay, thanks a lot
Now I'm a few steps further.
I installed the stock shelly firmware (Swicht1-1.0) with the curl comand.
Think that works.
But now I stuck at your step "Integrate it (By me was a reset needed)"
At my wifi is there now a new one with mg-F433C0.
I can connect with it, but dont know which IP adress I need to go to the shelly (or whatever now is the state of this device :D)