Allow us the option to upload a cover

Right now the platform allows us to only select a frame from the videos we upload to Instagram or Tiktok for the cover. It would be great to be able to upload the cover photo directly from the platform instead of having to do it on the platform once posted for example on Instagram. Sadly this cant be changed on tiktok once the post is published. So makes scheduling posts on tiktok useless if we need a specific cover for it.