My Spotify Canvas video does not have any audio/sound

Spotify Canvas videos do not require any embedded audio. They are silent.

If you managed to create and submit an 8 second video with sound, Spotify would automatically remove the audio anyway and ask you to submit a separate Master audio track to be used in conjunction with the silent 8 second video loop.

Rotor can provide provide the 8 second video-only loop you need - however, the main audio track you must upload separately to the Spotify artist page, this is what provides the sound.