In my experience, Google Chromecast and Apple TV are the best streaming devices to cast to your Samsung TV with.
If you have an older Samsung TV that doesn’t have Apple Airplay, and/or the screen mirroring feature isn’t working or available on your casting device, you can always get a third party streaming device to cast with. Your device should be successfully casting to your TV! Cast to Samsung TV using a separate streaming device Instead, stop on SETTINGS and then press ENTER. If you press UP, you’ll open the wrong menu. The key here is to stay hovering on SETTINGS and don’t press UP. You’ll then need to toggle all the way left until you land on SETTINGS. This will bring up the Samsung menu along the bottom of your TV. The first step to using Airplay is pressing the HOME button on your Samsung TV remote. We covered this option above, but here is a more in-depth explanation with pictures, in case you need it.