Projectors and sound bars make very poor combos. If the sound bar has HDMI in, many don't , then it should work. Long HDMI cable runs can also be problematic so make sure its a good quality one and note just because it's expensive doesn't necessarily mean its good quality. AVR's work so much better and can be simple at first and slowly upgraded. Used AVR's are dirt cheap if they don't support 4K.
"Smart enough to know better, to old to care" ------ Dedicated Bat Cave Home Theater, JVC RS49U/Mitsubishi HC7900DW Projector, 110" 16:9 Jamestown screen with variable power masking for CIW 2.50:1 to 16:9, Marantz 7009 with 7.1.4 Atmos with Ohm mains,3 DIY Subs (2 15" (1 ported, 1 sealed and a 12" 4th order bandpass), 1 DIY butt kicker, Custom Built HTPC, 18TB DroboFS NAS