When writing an article, you can insert a video using the Articles toolbar! The video option is the second icon from the left.

You can embed any video hosted on YouTube, Wistia or Vimeo. 

If you want to add a GIF, just select the image icon from this toolbar, and select a .gif file.

is there any option to insert videos von tiktok, or at least with an embed code?

I can add the video by the URL but when I add ?rel=0 to the end of the video URL, to keep related videos from popping up,  it does not disable the related videos. Can this be fixed?