As @makaiguy mentioned, BT is broadcasting the audio. Only they can provide an answer to this. If they're telling you to press the "red" button, their customer service staff obviously have no clue about what device you're using. No Roku remote has the colored buttons you see on remotes for other devices.
Dan Ultra (4640), Ultra (4670), Ultra (4800), Premiere (3920), Insignia 720p Roku TV, Sharp 4K Roku TV, Nvidia Shield, Windows 10 Pro x64 running Serviio and Plex on a wired Gigabit network.