Using a head unit, smart trainer and PM

This is all super specific depending upon the make and models of your devices, and support will have the best recommendation based upon what you’re working with!

From the ‘Welcome to the TrainerRoad Forum’ Page:
Have a question about the app, your training plan, or device? Reach out to support@trainerroad.com instead of posting here. Our support team has the best visibility and insight into your devices, workouts and adaptations, and will help get you the most efficient and effective answer to your question.