For youtube and vimeo we have native plugin which can help you do this.
For tiktok, you can try using rich text, add rich text element, and just paste tiktok link, it might work.
You must open this webpage in the browser from a non-mobile surface
Click the Share button (right-facing arrow icon), and then click Embed
From the popup window, simply copy and paste the code into the destination webpage, where you wish to attach the video. Voilà, the embedded video will automatically load on the page.