Hello @vencenty, welcome to Figma Forum. I don’t speak Chinese, so I hope it’s okay that I’m replying in English.
I checked in with Customer Support, and they’ve received your request. It’s under review as case: 2186159, and they’ll follow up with you directly.
In the meantime, you can see who has a Full seat under Admin → People. If someone other than your designer has a Full seat they don’t need, you can move them to a free View seat. You can also change seat approval settings so new paid seats need an admin’s approval first. This article covers both: There are additional charges in my Figma bill → My bill is higher than expected.
Hope this helps make things more clear, and thanks for your patience as the team follows up on your case.