I tried to use a HTML element, but it doesn’t seem possible: There is no document object that I can use to create arbitrary elements from javascript.
The post that you linked is about uploading to the media manager, whereas I am trying to upload it to a 3rd party service via a rest api. Are you saying that I should be uploading to the wix storage and then uploading the file to the 3rd party and deleting it from wix storage? (seems very heavy-handed)