To create a TikTok pixel, you must first have or create a TikTok Business Account and an Advertiser Account.
Once you have that setup, you can create pixels
This is similar to setting up a regular Postback in your Perform[cb] Portal.
Will this method track 100% of leads in TikTok?
Conversion API will track higher than a regular Pixel because regular pixels depend on cookies, which are blocked by Safari and Firefox, which means it will not work on iPhone devices.
However, even with Conversion API, TikTok is not allowed to track users that opted out of tracking on iOS14.5 or in EU. This is a TikTok limitation and applies to every platform.
Why does the % of tracking fluctuate?
This really depends on % of conversions received from iOS 14.5 users that have opted out of tracking. If your campaign is delivering to mostly iOS 14.5+ users, then you will see higher discrepancy.