Please checkout this article for further information on how to wire your your VTX to our iFlight FC or Stack!
https://iflightrc.freshdesk.com/support/solutions/articles/48001148115-firmware-wiring-factory-dumps
Did you setup your Betaflight VTX tables?
Please checkout following resource:
https://www.youtube.com/watch?v=thR2XA_0PLM
Our VTX tables can be found on our Google Database:
https://drive.google.com/drive/folders/1r3MNTBNYSzGeRXQg45j4IJVoW1Xjk7Y0
CAUTION:
The VTX Buttons can't be used if you're using SmartAudio or IRC Tramp (VTX Telemetry) to control your VTX through your OSD!