Sulfotransferase that utilizes 3'-phospho-5'-adenylyl sulfate (PAPS) to catalyze the transfer of a sulfo group to an N-unsubstituted glucosamine linked to a 2-O-sulfo iduronic acid unit on heparan sulfate (By similarity). Catalyzes the O-sulfation of glucosamine in GlcA2S-GlcNS (By similarity). Unlike HS3ST1/3-OST-1, does not convert non-anticoagulant heparan sulfate to anticoagulant heparan sulfate (By similarity). 3'-phosphoadenylyl sulfate + alpha-D-glucosaminyl-[heparan sulfate](n) = 3-sulfo-alpha-D-glucosaminyl-[heparan sulfate](n) + adenosine 3',5'-bisphosphate + H(+) Belongs to the sulfotransferase 1 family.