To upload files, in the message entry screen, click on “Go Advanced” button below the message field. When that opens, there is a list of “Additional Options”. One of the options is “Attach Files”, “Manage Attachments”. Open Manage Attachments and there is a list of acceptable file types, and file size limits.

I would suggest recording a log, and exporting as a .csv file, which you can upload here. Much more convenient to review than trying to extract data from a video.