Sulfotransferase that utilizes 3'-phospho-5'-adenylyl sulfate (PAPS) to catalyze the transfer of a sulfo group to the 3-O- position of an N-sulfoglucosamine residue in heparan sulfate (PubMed:34351732). Is able to install the 3-O-sulfo group in a disaccharide domain consisting of -GlcA2S-GlcNS- to form the -GlcA2S-GlcNS3S- sequence, and in -IdoA2S-GlcNS-IdoA2S- to form -IdoA2S-GlcNS3S- IdoA2S- (PubMed:34351732). Does not sulfate the -GlcA-GlcNS- IdoA2S- domain (PubMed:34351732). . This is the function of HS3ST4 (heparan sulfate-glucosamine 3-sulfotransferase 4, ENSG00000182601).