Set up accounts for other content providers on Apple TV
Some apps and content providers, such as Netflix, HBO NOW and Showtime, require that you sign in before using them. When you open the app to sign in or to set up an account, follow the onscreen instructions.
Tip: You can speak usernames and passwords. With the text entry field highlighted on screen, press and hold the Siri button 
on the remote, then speak letters, numbers and symbols instead of using the onscreen keyboard. Say “uppercase” to indicate an uppercase letter. For more information, see Use Siri dictation on Apple TV.
Automatically fill in a saved password from your iOS or iPadOS device
If you’ve saved passwords on your iOS device with iOS 12 or later, or on your iPadOS device with iPadOS 13 or later, you can autofill account passwords on Apple TV. A prompt appears on your iOS or iPadOS device when the password field appears on Apple TV.
On your iOS or iPadOS device, tap the account name field on the sign-in screen for the website or app.
Do one of the following:
Tap the suggested account.
Tap
, tap Other Passwords, then tap an account.The password is filled in. To see the password, tap
.
To enter an account or password that isn’t saved, tap 
on the sign-in screen.
Change app settings
Some apps may provide settings you can modify within the app.
To see what other options may be available, go to Settings > Apps on Apple TV, then select the app.