Garmin/Wahoo can control the resistance level too. Wahoo only used to work with the KICKR, now with works with all.
On your Roam, set the unit to Indoor. It'll then have a screen on the HAMMER for resistance level - watts and basic resistance. It can record the workout. Not sure if it'll do a planned workout.
On your phone, Saris has two apps Rouvy and Saris for this too. - EGR mode is the name
https://www.smartbiketrainers.com/6-...t-trainer-8681