This means that you must first create a personal account at Huggingface.co, then you must fill a request form for Meta, including whom you work for and in which position, submit the request to Meta and wait for it to be approved.
In my case the approval was received in about 10 minutes or so.
Presumably after that you are able to download the files, though I will have to see how easy it is to use your credentials from a CLI download program, because downloading a big LLM with a browser is completely impractical, as the transfer of the big files breaks very frequently so you need a download program like wget or curl, which will restart the interrupted transfers as often as necessary.