I suggest uploading directly to ani.social but there's an upload limit of 25MB. If your file is bigger than 25MB, then you will have to re-encode it so it's smaller. Something like https://8mb.video/ will make it easy.

Otherwise, you can use any external file host like https://catbox.moe/. I prefer if people upload directly to ani.social instead so we don't put too much load on others.