VTX smart port configuration on FC soft serial

How should I configure the Eachine TX805S smart VTX connected to serial port 6 of the FC OmnibusF4 Pro V2 to see and change the transmit power of the VTX? Thank you

LMGTFY - Video Transmitter Support — Copter documentation

Actually, by consulting the documentation on ardupilot Omnibus F4 Pro (on-board current sensor) and Omnibus F4 AIO (no sensor onboard) — Copter documentation I verified that I had connected the VTX smart port to the PWM8 pad. What should I do?

Need to connect it to a UART