Trying to load rJava package and getting error. Using MacOS X Catalina

Hi, and welcome!

For future reference, please see the FAQ: What's a reproducible example (`reprex`) and how do I do one? Using a reprex, complete with representative data will attract quicker and more answers. Not needed for this problem, though.

The error message shows that there is no installation of Java on the system. (If you ask me, that's just fine, but tastes differ.)

Because of Apple's improved security measures, installing it isn't necessarily click-and-go, but see