beforehand this should be possible here:
Structured workout sending to Sport Watches is a little bit different, every brand (Polar, Apple, Suunto, Garmin) use their own thing and it is more complex, you can use Training Peaks for this or your Garmin watch directly with Garmin Connect.
I run with Stryd and i made my own Library of running workout in Training Peaks based on the TR Triahtlon Plan and send them to Drews Interval App on my Forerunner 945, it works perfect for me.
Normaly it impossible to use power based running workouts with Garmin, because they don’t support native power, but the developer of Drews Interval App is very tricky!