Storyboard previews need a storyboard token and a manually built URL, not the playback token. And signed playback requires a JWT.

Context: Community reference (balo-app Mux skill on GitHub): storyboard hover previews dont work off the playback token. You need a storyboard token and you build the storyboard URL manually. Also, signed playback needs a JWT, so if your player 403s, check the token type before blaming the asset.