inserting a video fro my iMAC into a Word document

In Word 16.63.1, the Insert Movie will support .mov, .mp4, .m4v, but not .mkv. You will have to double-click on the movie object before it will present player controls and commence playing. The caveats about video formats and the audience for your Word document should dictate using industry standard encoding to avoid Mac only formats.

Use the Insert - Movie and it should work, however you need to check the format the movie you have is compatible with Word. This is not a Word forum, so you may need to do some additional research, By the way it is helpful if you ask more specific questions. Something like, "I have a 1 GB movie in .mv4 format that I'm trying to import into Office for Mac Word version 2019. I am trying to drag and drop the movie into Word but I am getting the following error message...."

Open word. In the top most screen menu: Insert > Movie