Need Help With Insuring Drivers to drive my cars, especially part time drivers

Started out by buying a car for one of my tenants to drive for Uber/Lyft and setting him up with a long term lease whereby at the end of the lease; he

owns the car!  Though that worked out well; I had him on my policy (as my pretend grandson!).

Now I wish to get more dirvers drive more cars that I own and lease to them; but wondered if someone knew how to get the driver to obtain his own insurance

on a daily, weekly or monthly basis!  Any numbers or names would be appreciated, Jeff  561-531-1440