Sign in with your Apple ID to the Apple TV app on Mac
To purchase and rent movies and TV shows or to subscribe to Apple TV channels on your Mac with the Apple TV app, you need an Apple ID. If you’ve purchased items from the Apple website, or if you have an iCloud account, you already have an Apple ID. If you don’t have an Apple ID, you can set one up using the Apple TV app.
Set up a new Apple ID in the Apple TV app
In the Apple TV app on your Mac, choose Account > Sign In.
Click Create New Apple ID and follow the onscreen instructions.
See the Apple Support article Manage and use your Apple ID.
If you have a PayPal account, you can use that as your payment method when you enter your credit card information. (PayPal isn’t accepted for payment in some countries or regions. For details, see the PayPal website).
Sign in to or out of the Apple TV app
After you set up an Apple ID, you can sign in to purchase or rent items, view or change your account information, and see your purchase history.
In the Apple TV app on your Mac, choose Account > Sign In (or Sign Out).
If you forgot your Apple ID or password, click Forgot Apple ID or Password? and follow the onscreen instructions.
When you finish using the store, you can sign out to prevent anyone else who has access to your computer from making purchases using your account.
See the Apple Support article Sign in with your Apple ID.