Welcome to the forum. The 380DA is a great boat. Good luck w/ yours.
Assuming that the TV bracket will be mounted onto the arch. Select a location close enough to existing openings, like the padded bolsters, retained w/ push / pull Christmas tree fasteners, or the speaker, so that those part(s) may be removed to permit placement of internal hardware, like an aluminum backing bar (preferred) or large fender washers (bare minimum), plus associated locking fasteners and nuts.