Copy Windows APP from one PC to another?

Greetings!

I just noticed a Store bought APP not being available for download anymore so I can't get it onto my new PC.
Apparently It's not even visible to me anymore when searching for it in my Store Library.

Where I DO still have access to it is on my old PC so slightly blue eyed I tried copying it over to my new one but that didn't quite work as planned as it's missing the Tile to launch ( and most likely it being registered to the System to begin with ) - Not that I actually expected for it to be THAT easy.

Doing some research It appears that Sideloading it would most likely be the answer to my question but my so far attempt in just packing the whole thing into a ZIP, renaming it into *.appx and running the created package Failed due to unknown reason - Yes, I'm a simple person

So yeah... Can anyone point me in the direction as to how to actually get this done?

Thanks in Advance =)