Your husband must have acquired resident status (or has a pending FORM I-485) based on a prior U-1 nonimmigrant visa before he can file the FORM I-929 on your behalf.
Are you being guided by an attorney?
as you mentioned that your husband is the holder of a U-1 visa, he may file Form I-929, Petitioning for you as a Qualifying Family Member of U-1 Non-immigrant with USCIS. as such, he would have to show that you would be subjected to “extreme hardship” if you not permitted to reside with him in the United States. I join my colleagues in strongly recommending that you consult an immigration attorney for this application process.