how to get data to use Customer File function on tiktok ads?

I realized that the customer file function of tiktok ads does not use phone numbers like google and facebook. How can I get IDFA/GAID data from the purchase website?

Or is there any way to collect IDFA/GAID from client?

I'm having the same issue, looking for a way to convert emails into those metrics if that's possible. Otherwise, I'll look into google dorking IDFA and GAID and get a new list while we wait for TikTok to accept regular lists. What a pain