Upload Meta Video

Gets a video into the user's Meta ad account and returns its video_id, WITHOUT leaving the chat. Three ways, depending on where the video is: (1) THE FILE IS ON THE USER'S COMPUTER without a link: a call with no arguments returns an upload link. You get a one time drop link to give them; they open it, drag the file in, and that is all they do. A call with ticket=<the returned token> reads the result for building the ad. The upload completes here; it does not require Ads Manager and does not need base64. (2) THEY HAVE A LINK (their own site, Drive, Dropbox, WeTransfer): pass video_url and the file is fetched server side and pushed to Meta, so share links that Meta itself cannot read still work. (3) A video already in the account: reuse its video_id, no upload needed. The video_id is reusable across ads. mp4, mov, m4v or webm, up to 300 MB.