Helium doesn't ship with Widevine DRM out of the box because it's an ungoogled-chromium fork. If you try to use Spotify, Netflix, or Crunchyroll, it'll just fail.
You can fix this easily by dropping the Widevine files from a browser that already has them (like Chrome or Brave) right into Helium's data folders. Since Helium scans these directories when it boots up, it'll pick them up automatically.
Here's the quick way to copy them over manually depending on your OS.