Hi @tarzanboy
Welcome to the Sonos Community, and thanks for the support!
Sonos generally does not work well with projectors as we require a HDMI-ARC/eARC port on the display device, and projectors usually do not include these, though it’s looking like more and more newer models do.
The only other way to get Home Theatre sound into a Sonos product is via the Optical Adaptor that will have come with your Beam - fit the HDMI cable to the Beam, the adaptor to the other end of the cable, and plug the adaptor into the optical output socket on the projector - which, obviously, needs to exist. Using optical, you will be restricted to Dolby Digital, DTS and PCM (stereo) audio only - no Atmos or LPCM will be available.
If the projector has no optical output, a workaround would be to buy a HDMI audio stripper (to go between the FireStick and the projector) which provides an optical output, or a more advanced device like the Arcana to provide full ARC/eARC for support of more audio formats. Please note that these solutions are not supported by Sonos, but should work.
There is no way to stream Home Theatre audio from a FireStick to Sonos wirelessly.
I hope this helps.