your best bet would be to contact the state board and ask. My guess is specifically California probably wouldn’t allow it (though I do not know for sure) only because they previously had such a difficult state board exam, I doubt that they would be lenient with people who hadn’t passed and wanted to practice under someone else. They did get rid of that exam this year so it’s at least a bit easier to get a license there! I would definitely contact their board though since they would have the official answer.