There shouldn't be anything to prevent you from putting links in your posts or tying them, for example, to a "Learn More" button. Typically most people use links going to their website, but yes, you should be able to use a TikTok link. I'd strongly recommend that the video is not something that would be considered misleading or spammy, the video should be consistent with the content of the post or you might have other challenges with Google approving posts.
New advertising option:
A review of your product or service posted by a Sterling Sky employee. This will also be shared on the Sterling Sky & LSF Twitter accounts, our Facebook group, LinkedIn, and both newsletters.