Just replace the URL with the one for your desired video. The video URL should like the one I have below, though you don’t need to remove the query parameters - if it doesn’t you may need to Share, Copy Link, and use the copied link instead of the URL bar. This is especially true if navigating among tabs on the web or something.
You may need to wrap the url in double quotes. IME it varies by device.
On iOS there are Shortcuts that integrate with yt-dlp, and on Android you can do the same with Tasker and the Tasker - Termux plugin. Make sure to install the F-Droid versions.
You can also save many Tiktok videos through the app’s Share dialog, though creators can disallow that content wide.