Answer: Firebase Storage: String does not match format 'base64': Invalid character found

if image is a base64 data URL you can use 'data_url' parameter and metadata:

function uploadImage(image){
  const user = getCurrentUser();
  const refImage = app.storage().ref(`profileImages/${user.uid}`);

  refImage.putString(image, 'data_url', {contentType:’image/jpg’}).then(() => {
    console.log('Image uploaded');
  });
}