The EMAX ExpressLRS variant of the E8 transmitter uses a custom serial configurator application for applying settings to the transmitter.
Open application and click "Language" in the bottom right corner to change to English.
Connect your transmitter via USB-C cable and click "Connect"
Click "Read" to view the current settings of the ELRS E8.
If you wish to change settings, change the settings in the dropdowns to what you would like to use and then click "Write" to apply them.
Serial Configurator Download: https://drive.google.com/file/d/1ZuoizXaVmXZt6aoeY0Vw3X-NA8ks5f9p/view?usp=sharing