Don’t know about your specific FC, but normally you can just connect the servo to one of the PWM outs that don’t belong to the main motor group, set the servo function to a free RCIN channel and set your pot to that channel in your Tx.
Don’t know about your specific FC, but normally you can just connect the servo to one of the PWM outs that don’t belong to the main motor group, set the servo function to a free RCIN channel and set your pot to that channel in your Tx.