Pjiang, XBT & xdjm: H1B extension at Vermont Service Center. Wha

I am filing H1B extension petition, but Which address should I send it to? I feel a little dumb... Thanks.

USCIS
Vermont Service Center
ATTN: I-129
75 Lower Welden Street
St. Albans, VT 05479-0001

or

USCIS
Vermont Service Center
ATTN: H-1B U.S. Masters Cap
1A Lemnah Drive
St. Albans. VT 05479-0001