I finally got it to upload.
I could NOT get the HEX file to work.
I could NOT get the Grbl Upload example to compile.
It turns out that the files need to be included for the Grbl Upload example to compile / load were not being added to the library automatically like they should. I manually added the grbl folder with all the necessary .h files to the Arduino Library folder on my PC (I found the path in the software’s settings)
Once I did that the Grbl Upload example compiled and uploaded correctly.