React Native: Error decoding image data from CameraRoll.saveToCameraRoll

I'm getting a warning sign, saying

Possible: Unhandled Promise Rejection: Error: Error decoding image data

This is my code.

for (let media of mediaArray) {   
  await CameraRoll.saveToCameraRoll(
    'https://someurl.mp4',
  ); 
}

I was able to get this to work with a url that has a .jpg, but when I tried a .mp4 url, it doesn't work. I know the url is correct, but not sure why I'm getting this? Am I missing something if I have to save both either photo or video?