Pokemon Home is finally available on the Nintendo Switch. Its mobile app is also available on Android & iOS. Pokémon HOME is a cloud service for Nintendo Switch and compatible mobile devices designed as a place where all Pokémon can gather.
However, many players are experiencing issues with the mobile app. They are getting an error message while connecting to Nintendo Account. You can check the complaints of a few users.
Some players have told that players should not use the touch ID & Face ID method. Manual entering of Login ID & Password has worked for them. So, you can give this workaround a try. It is the first day of the launch, so the servers are currently overloaded which is resulting in connection errors for many players. Rest assured, we are keeping a close tab on this issue and will update you with more information whenever it arrives.