Getting Heart Rate Lock outside of a Workout

How can I get the watch to lock onto the heart rate before starting a workout, in the same way that precision start works on the Ultra?

In the past it required a special permission and I requested this several times without hearing back. I assume this was because the permission was intended for other app types (meditation etc).

However now that precision start is available in the native app it would be great to provide it in my workout app. I looked around for the permission form again but couldn't find it so I was wondering if anyone knows how to do this?

Thanks.