Screen mirroring does not work

I have an Apple iPad Air 2, an iPhone 6s and an iPad 4th generation. None of these devices will now work in screen mirroring mode with my Samsung tv.

I have scoured these forums and the Internet now for days to try to find a solution but it is impossible. So believe me, I have tried everything. 😢

I am probably clutching at straws but perhaps someone can help. I don't want to connect my devices via a hdmi cable, I want to connect by screen mirroring. I also don't own Apple TV so this is not a route I wish to go down either.