Airspeed sensor and Omnibus F4 pro FC

Hi How do you connect ( what pin etc) a anolouge airspeed sensor to the omnibus f4 pro running with arduplane.

depending on your exact board variant the RSSI pin would likely be the best option. that‘s PIN 0 in runtime.
check https://ardupilot.org/plane/docs/common-omnibusf4pro.html for reference.