Aus der Edge tx Doku:
Make sure you selected the correct Internal Module in the system. To do this, hold down the SYS key, and go to the “Hardware” page. Scroll down to “Internal Module”, and choose the right module. For example, for 4in1 multi-protocol module, select “MULTI”. For ELRS, select “CRSF”. If you failed to do this, you are not going to get the right option in the “Internal RF” in Model Setup.