The way I download a TikTok Video without a watermark is by using the app SnapTik which is a completely free TikTok video downloading app that does not have a watermark on the videos.
You can download the video from TikTok by selecting the video you want to download on TikTok, tapping the Share button, and choosing the Copy Link option.
Then you just paste the link into SnapTik's designated field and you'll have your watermark-free video in just a couple of seconds.
And the, SnapTik app is completely free.