Unable to Make calls using Realtime & PJSIP

Hello,

I am new to Asterisk and I installed Asterisk on My Ubuntu Server 18.04 and Configured Realtime using following tutorials.
https://linuxize.com/post/how-to-install-asterisk-on-ubuntu-18-04/
https://wiki.asterisk.org/wiki/display/AST/Setting+up+PJSIP+Realtime

I did exactly what they are teaching on above tutorials and having below error and unable to make calls.

[Oct 2 11:32:09] ERROR[31856]: res_pjsip.c:3533 ast_sip_create_dialog_uac: Endpoint ‘101’: Could not create dialog to invalid URI ‘101’. Is endpoint registered and reachable?
[Oct 2 11:32:09] ERROR[31856]: chan_pjsip.c:2509 request: Failed to create outgoing session to endpoint ‘101’
[Oct 2 11:32:09] WARNING[31882][C-00000007]: app_dial.c:2578 dial_exec_full: Unable to create channel of type ‘PJSIP’ (cause 3 - No route to destination)

Note : Both 101 and 102 extensions are Registered successfully but cant make calls

What’s the output of the following:

*CLI> pjsip show endpoints

And:

*CLI> pjsip show aors

And:

*CLI> pjsip show contacts

Also how is the channel being dialed? What’s the dialplan look like for that extension?