If you are using or were previously using the Decora Smart Home app, you can now use the My Leviton app for maintenance of your Decora Smart 1st Generation (DH***) and 2nd Generation (D2***) HomeKit® devices. You DO NOT need to create or log into a My Leviton account.
Instead, you will select the "Use with HomeKit® Only" link on the My Leviton Login screen.