If the above-described methods have not worked for you then, unfortunately, your Samsung Galaxy smartphone device does not support Screen Mirroring feature.
Indeed, one of the biggest flaws in Samsung Galaxy J7 smartphone is that it has no support for a Screen Mirroring Application.
Your best bet is Chromecast.
How do I connect my Samsung phone to my Samsung TV?
To connect wirelessly, go to your phone’s Settings, then tap on Connections > Screen mirroring. Turn mirroring on, and your compatible HDTV, Blu-ray player, or AllShare Hub should appear in the device list. Choose your device and mirroring will begin automatically.12 Jun 2013
How do I connect to Samsung AnyCast?
Step 1: Connect WiFi cable (micro USB head) to AnyCast dongle main body. Step 2: Plug the AnyCast into the HDMI port of your TV and switch to the right input source. Step 3: Plug USB cable into an external USB power adapter.
Does Samsung Galaxy 7 have screen mirroring?
No, Samsung Galaxy On7 Pro doesn’t have screen mirroring feature. But you can download “AllCast app” from play store and use it to cast your screen.
Photo in the article by “ويكيبيديا”