Looking for Aerial connection point under dash

[Paul2415]

Got a 2019 transit on a V363 shape, installing a new alpine halo 9 radio, removed my old radio, standard fm with no additional screen,so basic as it cones, aerial lead on back is a very small smb style plug, no large standard style fm lead ?, under wing mounted aerial is a big orange lead going into dash drivers side, where does it go and I'm guessing there is a conversion box of sorts?? Any idea of where I find this ? Which panels etc do I need to remove? As want the fm lead and want to convert to dab, thanks in advance.