PJSIP uses a separate configuration entry to do IP based matching. It’s configured using the “type=identify” section and is documented on the wiki[1]. You can also find an example[2].
[1] https://wiki.asterisk.org/wiki/display/AST/Asterisk+13+Configuration_res_pjsip_endpoint_identifier_ip
[2] https://wiki.asterisk.org/wiki/display/AST/Migrating+from+chan_sip+to+res_pjsip#Migratingfromchan_siptores_pjsip-ExampleSIPTrunkConfiguration