If a passcode appears on your Roku screen, enter the code on your Mac.

At the top of your screen, click the AirPlay button in the menu bar and select your Roku device from the available devices list.

On the Displays page, check “the box next to Show mirroring options in the menu bar when available”.

If the AirPlay icon in the menu bar at the top of your screen is not visible, open “System Preferences” and click on “Displays”.

You can mirror your entire screen to your Roku from the menu bar on your Mac.

Enter the passcode on your Mac if it appears on your TV screen.

Now from the available list, choose your Apple TV.

Now on your Mac go to the top menu, click System Preferences and then “Display” and click the “Show Mirroring Options in Menu Bar when available”.

First, connect your Mac to the same Wi-Fi network as your Apple TV.

Here is how to AirPlay from a Mac to a TV. With Apple TV you can use your TV as an extra screen or mirror the entire display of your Mac. You can adjust the size accordingly on your computer screen.

It will also exit if you disconnect the cable or shut down/sleep the other Mac.If you want to mirror your Mac to TV, simply activate AirPlay at the right place, and it will begin mirroring. To exit TDM, just press Command + F2 again. Your target iMac will now display the desktop of the other, connected Mac. Press Command (⌘) + F2 on the keyboard of the iMac that you want to use as a display.Connect the Mini DisplayPort or Thunderbolt cable between the two computers.Turn on your iMac and make sure the other Mac is logged in.A supported iMac with OS X v10.6.1 or later.A Thunderbolt cable or a Mini DisplayPort to Mini DisplayPort cable.If your Mac has Thunderbolt 3 (USB-C) ports, you can connect it using the Apple Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter. A Mac notebook or desktop with a Mini DisplayPort or Thunderbolt port.Apple has a support page about this, with system requirements and display options. It’s called Target Display Mode, and it’s easy to start using. This gives you a bigger screen without needing to buy another screen. If you have both a MacBook and an iMac, you can use the iMac as a secondary display for the MacBook, or use an iMac as a display for another iMac.

How to turn on macbook air play display