Original Message

... must register with the State if using it as a regular helistop (not a licence, but a registration).

This is the State of Florida regulations for airport:

https://www.flrules.org/gateway/ChapterHome.asp?Chapter=14-60

 ;

And, here is a Florida listing of Municode for the county, or city you are looking for, and when you go to any, make sure you look at both the ordinances and the land development codes (sometimes listed separately).

https://library.municode.com/fl

P.S. When a county EMS calls an air ambulance helicopter to the scene and sets up an LZ, they are doing so using their EMS authority.