-It is immigrant fee. When your spouse got the immigrant visa, this fee requirement should be addressed in the document the VO gave to your spouse.
If you don't pay it, the green card will never be issued to your spouse. Check this website for how to pay it:
https://www.uscis.gov/file-online/uscis-immigrant-fee
另外如果一直没有收到绿卡应该与哪个部门联系? 多谢8老师指教!