Help with information for working visa (Puerto Rico)

I am a British citizen with a visitor's visa and wanted to know the requirements for getting a working visa. I have been searching online on the embassy's site, but can't get anything straightforward. Or, can I go to the Immigration Department and get approval or work permit from them to work in Puerto Rico?

Is there anyone on the forum who can guide me whom should I go to or where to go?

Thanks.