I would expect a ftgxmip adapter to be either press or sweat . a bit confusing to me as well. I would think you could use a standard street 90 on press as well (provided you soldered prior to fitting and pressing)
You cannot use standard fittings in a press system. They make special fitting adapters for press systems. They are longer and the stops clear the press tool when you crimp them. I've been there and had this problem.