If your plan includes downloads you will find the option to the right of the video player on the Broadcast Details page.
Simply click Download Recording - Generate MP4 Recording - and once the process is done click Download Recording to download the MP4 file to your device.
NOTE: If you would like to send the file to someone else you can simply click the Copy Download Link once the MP4 has been generated and that will copy a link to your clipboard that you can send to others to download. This link expires after 30 days.
If you need more help, check out this video on How to Download a BoxCast Broadcast