If you want to switch to an audio-only call, i.e., you want to neither receive anyone’s video nor publish your video, you can use EnxRoom.setAudioOnlyMode() method. This method acts as a toggle to switch between audio-only and audio-video calls.
room.setAudioOnlyMode(true); // Switched to Audio-Only call room.setAudioOnlyMode(false); // Switched back to Audio-Video call
Learn more about How to change to Audio-only Call here.