Disable autoplay in browser
Unfortunately, all browsers are set by default so that videos are started automatically when the corresponding page is called, even if the webmaster of the visited page has disabled said autoplay. Here I explain briefly how you can turn off this autoplay in your browser. After that you can call the videos as usual, manually.
In the upper right corner of Firefox, click on the 3 dashes and select Settings.
Select "Privacy and Security" from the menu on the left.
Scroll down to the item "AutoPlay". On the right click on "Settings".
A window opens in which you can select "Block media with audio".
Select this item. No more videos will be played automatically, but you can access them manually.
Click on the Opera icon at the top left and select Settings.
Select "Advanced" in the menu field on the left.
Select the "Features" menu item.
Scroll down to the submenu item "Video pop-out".
There on the right side switch off by clicking the small blue field, so that the field is grayed out.
Videos can also be started manually here in the browser.
Unfortunately, Chrome doesn't let you disable autoplay, only the sound throughout. But that's not the point. Nobody knows what the developers were thinking.
At the top right of the browser, click on the 3 dots and go to Settings.
In the left field click on Cookies and Website settings.
Scroll down quite far to the point "Automatic media playback".
Select the item "Restrict" and restart the browser.