If I do an outdoor workout without a power meter, how can the RPE be displayed on a garmin 1030 plus?
It can’t. RPE = Rate of Perceived Exertion. This isn’t a metric that can be calculated, it literally is your perception of how hard you are going. So just ask yourself at any point: how hard does this ride feel?
Measure the amount of blood on the screen.
It might be in the workout notes? I’ve always used HR or power so I don’t know.
I think the OP is looking for their garmin to tell them the RPE they are shooting for during the workout. I’m not aware of a way to do this. I think it will be shown when each step begins in the step notes, but beyond that I don’t think there is a way to reference it on the garmin.