Can someone help me show me how to duplicate my screen in Linux?
 

I bought a J5create hdmi extender kit and have it working but it only shows my laptop background on my tv.

It doesn't show what is on the screen .
I'm running linux on my laptop and and need to know how to share screen, duplicate screen or whatever so I can see everything I'm doing on the tv screen. I know I'm close, but need that last step. Thank you.

You're trying to mirror what's on your laptop screen to your TV using HDMI? Sounds like it's using your TV as an extended background instead of a mirrored display. Does it work when you directly connect your laptop to the TV using HDMI? I'm not familiar with the HDMI extender you're using, but have you verified that it's even possible with Linux? What Linux distro?

I am sure it does with a straight hdmi cable. I am trying to set up the wireless extender to get rid of the cables.

I am using Kubuntu linux

and I think you are right that it is using my tv as an extended screen. I slide my mouse off the end and it comes up on the tv . I am close here, just need a setting change of some kind

If it's designated as an extended desktop, can you simply drag the window you're wanting to mirror over to the extended desktop? Just as you would slide the mouse off the end to display on the TV?

It is not designed to be an extended desktop. But this did work , and I can play with it like this, I don't want to keep it this way.

It's designed to be a wireless hdmi cable extender not a desktop extender.

Well, I'm confused and drunk. But glad to hear it did work.

Not sure what you mean by a wireless html cable extender. All those things seems to be contradictory. But again... drunk as shit... whooo!

you did help me fish. I moved the screen to the TV and was trying to resize it and a screen popped up and I was able to duplicate the screen. But I don't know how to get back to that screen again because I need to do separate screen sizes.