Posting to save someone grief. I missed the Charts during install, and then installed the wrong ones which led to hours of confusion, with some forums claiming it’s not possible now that charts are not free.
You can build and run QGroundControl on the free QT. If you are seeing the QT: Charts error, do
open -a ~/Qt/MaintenanceTool.app/
and put a checkmark beside the ‘Qt Charts’ under QT->QT 5.12.6 (or what you are using) NOT the ‘Qt Charts’ under ‘Additional Libraries’