Video from iPhone 8 uploaded to my iCloud (and MacBook Air) will not play

Thank you for taking a moment to consider.... Uploaded iPhone 8 photos and videos to iCloud and MacBook Air [Details: (13-inch, Mid 2013), Processor 1.3 GHz Intel Core i5, Memory 4GB 1600 MHz DDr3]

When I am in "Photos" and select a video, the pop-up states "Cannot Play File and asks if want to open in Quick Time Player. Selecting OK, the video converts to "IMG_1234.MOV" and indicates to see if additional software is available that will enable QuickTime Player to open the movie. I select Tell Me More and it takes me to this forum If an audio or video file doesn't play on Mac - Apple Support which confuses me even further, lol...any ideas are welcome. Thank you again for your time and consideration...