Apple TV +

What is your model Apple TV? Identify your Apple TV model - Apple Support

Apple TV+ is compatible with Apple TV box (3rd generation or later). Unfortunately, that excludes 2nd generation, even for AirPlay.

You may still be able to AirPlay content from the iTunes Store (i.e. movies for buy or rent) to a 2nd generation model.

You may want to re-consider. If you are using an Apple TV 2 or Apple TV 3 you are shorting yourself on a LOT of content available. The benefit of the Apple TV4K is it has the App Store which means you can have thousands (no joke) more channels, you have Apple Arcade (if you like games) and much more. Also, macsales.com has the 1st generation Apple TV 4K for sale for $119. Finally, you can view 4K content assuming you have a 4K TV.

In other words for $119 you will have a HUGE upgrade! Finally, something of note you can subscribe to Apple TV + for $49.99 per year which is cheaper than $4.99 per month!

Please Identify your Apple TV model and then we can answer your question.