Health app data sharing with other apps

I just got a new iPhone Xs Max. Previously my iPhone shared Health data with the Noom app (i.e., active calories and steps). My Noom app indicates that data sharing is allowed, however, data are only going from Noom to Health and not vice versa. When I go into Health and Activity, where it says "apps allowed to read data" my screen does not have a toggle to turn that "on" and underneath it says "none" greyed out. The same is true when I click on Steps. I would really like this information to be shared with the Noom app so I get credit for my exercise and steps! How do I get this to work?