Remote queue agents on another FreePBX server

Hi, the queue modules wiki shows:
prefix an agent number with S, P, X, Z, D, or A which the page says to be dialed as an Asterisk device of type SIP, PJSIP, IAX2, ZAP, DAHDI, or Agent

When trying to add a static remote agent as [email protected] save/apply and go back into queue settings it shows S8731.0 which is useless.

One way it I have found to make it work is to create a custom extension and in the Dial field add the SIP/[email protected]

Looking at the wiki again, it doesn’t say one needs to add the custom extension. Wondering if someone can tell me what has to be entered in the Static Agent so it would dial the SIP URI.

Thanks,