If you see a message on your screen telling you to go to DisneyPlus.com/Begin, all you need to do is the following steps:
Go to DisneyPlus.com/begin. Enter the 8-digit code you see on your TV. Click the Settings. Enter your code and click Apply Now. Click the Continue button. Head back to your preferred device and enjoy Disneyplus. Click the Character icon in the top right corner.