SRM Slope input

Hello All,

I have searched and have not been able to find the answer to this - apologies if it has been answered before.

I cannot find anywhere in the system to input the slope for my SRM (previous Shimano arm version).

To my understanding; the SRM broadcasts Hz/Nm and the reciever (usually a headunit) needs that particular power meter’s calibration number (slope) input into it to calculate and display/record Watts. SRM does not broadcast Watts.

Garmin has a box for this, as does SRM’s PC8 head unit.

But I can’t find anywhere in Trainerroad (Mac or Android app) to input the SRM’s slope?

This is the true calibration, the zero offset just takes the static reading Hz/Nm and zeros it before each ride.

Am I missing something?
Does TR just use a notional/average slope for SRM?

If you change the slope on the SRM head unit or Garmin it sends it that value to the SRM itself so that it reports the correct power to TrainerRoad or any other device