Dang, it looks so cool, and I was exited to try it out but when it finished downloading I clicked open and it said look for a app to use in the microsoft store ):>. Pls help or make it a .zip file pls.
It doesn't need to be fixed, you just need to download a program capable of extracting rar files like 7zip or Winrar. 7zip definitely has a Mac version. Then you'll probably need to download the Mac version of GZDoom and run the ipk3 file found in the rar with it. 7z and rar files are extremely common archive formats and Windows doesn't natively support rar files either anyway.
Just download 7zip and extract the rar file with that. Even Windows doesn't natively support rar. You need to use a program such as 7zip or Winrar. 7z and rar are extremely common formats by the way, so one way or the other you are going to want to eventually get a program that can extract them or you are going to miss out on a ton of stuff.