Sip notify spa-reboot syntax

I found some threads referencing that from the asterisk CLI the command "sip notify "

However, I have been unable to locate any specific documentation for this command, and when I attempt this command for type spa-reboot, there is simply an error:

pbx*CLI> sip notify spa-reboot 100
Could not create address for ‘100’
[2017-06-05 17:23:57] WARNING[28363]: chan_sip.c:6277 create_addr: Purely numeric hostname (100), and not a peer–rejecting!

I have been unable to determine what the expected syntax is for an extension/peer, as other syntax are also not accepted.

What is the correct syntax, or where is the documentation for this command?

when you type sip notify (then press the TAB key) what are your options. Enter the type of phone followed by extension
Not all phones are supported.

I wasn’t getting any output hitting tab, but then I went back and looked - the endpoints are on pjsip, not sip; so that was why. Once I changed from “sip” to “pjsip” things started behaving as expected.