SIP_HEADER not registered error?

General Help
1

I get this error when I try to extract the Sip header when I get a call. The syntax seems right and I have also enable pai in FreePBX SIP settings to obtain this. But, still seems it’s throwing this error. I am using an Asterisk 13 system.

ERROR[4035][C-00000002]:

pbx.c:4343 ast_func_read: Function SIP_HEADER not registered

– Executing [s@easybell-incoming:1]

NoOp(“PJSIP/easybell-incoming-00000005”, “”) in new stack

The context file :

exten => s,1,NoOp(${SIP_HEADER(P-Asserted-Identity)})

2

You can’t use SIP_HEADER with PJSIP channels. You need to read up on the application PJSIP_HEADER.