1. Open the live broadcast software or platform and enter the live broadcast settings page.

2. Find related options such as "Video Settings" or "Playback Settings", which can be found in the settings menu of the live broadcast software or platform.

3. In the video settings or playback settings, select options such as "Add Video" or "Upload Video" and select the video file you want to play.

4. After the video is uploaded, set the playback mode of the video, whether to play automatically, loop, and whether to display the control bar.

5. Click the "OK" or "Save" button to complete the video playback settings.