: Click the Download icon in Companion. This sends a request to the OpenTX build servers to generate a custom .bin file for your radio's options.
If you just want to copy a model from an old radio, use (the latest). It can actually import older 2.1.9 EEPE files and convert them to the modern format. You don't need to flash your radio to 2.1.9 just to look at an old backup. opentx 2.1.9 download
Since the main OpenTX website often prioritizes the latest builds, you usually have to look in the OpenTX 2.1 Release Archive. : Click the Download icon in Companion