If you have iCloud enabled, visit iCloud.com on your computer, sign in, and download the video directly from the Photos section.
If you are downloading to a Windows PC, you may need the HEVC Video Extensions from the Microsoft Store to play the file, as modern iPhones record in a high-efficiency format. Download IMG 7241 MOV
If using a browser-based download (like iCloud or Drive), stay on a stable Wi-Fi connection. Long videos often fail over cellular data due to connection "timeouts." If you have iCloud enabled, visit iCloud