My Parents are stuck in US due to COVID 19. They are on B2 visa and their authorized stay as per I-94 is expiring on April 21, 2020. We are in the process of filing I-539 for extending their stay.
If I go through online process then I need to submit individual applications for my mum and dad separately and so fees for both need to be paid separately. i.e. $370+$85/member. But if I mail I-539 then we can apply with co-applicant and fees need to be paid for single applicant i.e. total of $370+$170. This seems to be very economical to us and so going via mail process. But I am not able to figure out exact mailing address as there are offices in different locations and accepting different categories of forms.
Can someone help me with the exact mailing address for I-539 form. I am currently residing in Alabama state.