A local fab shop should be able to make you one or your local parker dealer should be able to get it from parker for you. My 2530 (a 2019 I bought in March) did not have the rocket launcher installed at delivery but was on the bill of sale. The boat was shipped to the dealer without it installed and parker got the part to the dealer for install. Same went for the coaming pads in the cockpit. The timeline to get it delivered to the dealer was not that long when the dealer told parker they didn't ship the parts with the boat.
On my 2120 (boat before the 2530) that didn't have one I got it fabricated at S&S marine in Norfolk, VA. One thing I liked on the old one is all the holes in the roof were outside the cabin. the leg going FWD in the center for additional support turned down before the back wall which isnt the case with the factory one I just got on the new boat.