Please be more specific.

PS:

What browser do you use? IE？

Open the Tools-Internet option in the browser's menu bar, switch to the Advanced tab in the pop-up window, find the "Multimedia" item in the middle part, and see if there are items such as "Play animation in the webpage" ... Sound and "... Video" selected. If they are not selected, select them.

Or Internet options, switch to the Security tab, click Custom Level, and then select Security Level-Medium.

Another way is:

Select "Trusted Sites" at the top of the security label interface, and then click the "Sites" button.

At the bottom of the interface, "Require all sites in this area to perform server authentication (/xueshudongtai/videonotpasshelp.htm)" will pop up.