Hi George - welcome to the community and thanks for posting. If you’ve followed the steps to manually authorize the device in the SmartThings mobile app and then immediately check your SharpTools User page, does the device show up?
From your User Page, you can tap the
...next to a location to see which devices are authorized for that location.
Note that after you’ve done the manual authorization, if you proceed through the authorization process starting from your SharpTools User Page → Manage Connections, that can cause the device to become unauthorized again. So you’ll want to check after doing the manual authorization and before taking any other actions.