What is this spucatum tauri, "Federal Firearms License Required"?
That ad is more than a year old; doubtful any are for sale anymore.
Regardless, as with all handguns (and most, but not all, long guns) shipped interstate within the United States, a FFL01 is required to accept delivery. In the case of that ad, if you were to put in an order, it would have to be shipped to a FFL01, who then notifies you when it arrives. You then visit the FFL01, fill out an ATF Form 4473, have a background check done through NICS, and if all clear (and depending upon the laws of your particular state), the FFL01 transfers said weapon to you.