The processing speed depends on several factors. Once the video gets rendered it will be available for Download.
Video Duration: Longer videos will take longer to process.
Video Quality: Videos with higher resolutions take longer to process.
Internet connection: Make sure you're connected to a stable internet connection.
If the upload process is taking a little bit of time you will see the video rendering loading on top of the video in the preview page.
Once the render is complete please click on the hamburger option on top of the video.
Locate the download option at the top-right corner. Please click on it and the video will get downloaded to your computer.