If you aren't currently logged into your Outlook account, do so with your Outlook email address and password. It's in the top left corner of your Outlook window.  You can also click Upload at the top of this screen, select Files, and select your video from there.  Your video should begin uploading immediately, but it may take a long time to complete this process. You'll need to keep the OneDrive page open until your file's upload completes. Now you're ready to send your email. It's at the top of the page, directly above the "Inbox" heading. You'll find this next to a paperclip icon above your new email section on the left side of your screen. This should be at the top of the page.   Unless your file is less than 20 gigabytes in size, this will be the only available option. These will include your recipient's email address, a subject field, and email text. Your video file will be shared in the form of a link. Once your recipient opens the file by clicking the link, they will have the option to download the file. Unlike with Gmail, files sent with OneDrive are automatically assumed to be shared with your recipient.

TL;DR in Vietnamese:
Truy cập trang chủ Outlook . Nhấp vào icon hình chín dấu chấm nằm ở góc trái cửa sổ Outlook. Chọn OneDrive. Nhấp chuột, kéo và thả file vào cửa sổ OneDrive . Đóng tab OneDrive sau khi quá trình này hoàn thành. Nhấp vào +New hay +Mới. Nhấp chuột vào Attach. Chọn ứng dụng OneDrive ở đầu trang. Chọn file video của bạn. Nhấp vào Next hay Tiếp theo. Chọn tiếp Attach as a OneDrive file hoặc Chia sẻ dưới dạng liên kết OneDrive. Nhập chi tiết email. Nhấp Send.