Opt-in to beta program for reMarkable?

How can I opt in to the beta program for the reMarkable 2? According to Reddit this seems to be a new feature:

But under General > Version I don’t see the beta option. How do I enable this?

I see it in the “Software” screen just under the “Automatic Updates” toggle.

The beta program already has version 2.7.0.30 available so I’m hoping reMarkable will keep coming out with new software releases for beta program users regularly.