How to create MacOS Mojave virtual machine in VMWare Fusion 11? Need ".app" file?

I am trying to create a MacOS Mojave virtual machine in VMWare Fusion 11. I need it so that I can run legacy software that will not run in Catalina when I upgrade. According to the VMWare Fusion 11 Help instructions, I need an ".app" file to install the Mojave guest OS. I tried using the dmg file that I found but that doesnt work. I spent half a day on Apple support finally reaching a supervisor and he literally hung up on me immediately after I told him the problem. VMWare tech support couldnt help but they at least say they will look into it and call me back. Anybody have any experience with this? Thanks in advance.