Trying to download Stencyl on mac but it doesn't work

Hi, I am trying to download Stencyl on my Macbook with MacOS Catalina 10.15.4 but it doesn't work. I've tried to download the .dmg and the zipped file but I can't open it. Can somebody help me, please? Thank you. 

Try copying the actual Stencyl app itself to the desktop (I mean the Stencyl icon), and then copying it back over the top of the one in your Applications folder (or wherever you run it from)