Since Betaflight has not yet released the official firmware that could supports the SPI ExpressLRS protocol, the current version is the Beta version .
Betaflight will update it to their official target soon. Please feel free to contact with us if you have any issues with this Beta version Firmware
Firmware download: ELRS F4 2G4_Betaflight_4.3.0_STM32F411_1.0.0-RC5 and Diff Document
ExpressLRS TX firmware(which could bind with ELRS F4 2G4) download: ELRS F4 2G4 TX Firmware RC3
This is the correct interface of 2.4GHz TX module that could bind with ELRS F4 2G4 flight controller
This is the correct CLI configuration of SPI ExpressLRS receiver
Change packet rate for the SPI Receiver command in the CLI tab
Set expresslrs_rate_index = 0
Allowed range: 0 – 4
Default value: 0
The packet rate of the TX module should be the same with SPI receiver , so that the link could be established.