Here you used to be able to find some experimental 64 bit builds of versions of EasyABC, and some related material. However this work was never finished.
Fortunately another developer, Frédéric Aupepin, has taken this on and put together a much better version which works well on MacOS Catalena and later. You can download what I think is his latest version (as of January 2021) from here:
https://drive.google.com/file/d/1mnXH6DD_PYFSrjyLvFpJ_m0ZA90qgmaG/view?usp=sharing
You might want to check on the abcusers@groups.io mailing list or the EasyABC page on SourceForge to see if there has been any further development on this.
Jon Warbrick