Installation problem on Imac

I tried to download fSpy on my Imac and downloaded the file:

fspy_1.0.3-X86_64.Applemage

To open it, Apple asks for an app to open it, but I don’t know which app to use for that. Is there no other way to download the program?
Thank you.

An AppImage file is for Linux. Try the .dmg file.

I’ll try that. Thank you!