AutoDial out- Customer press 4 to Dial Back - Fail

I tried to config that when customer press 4, they will auto Dial back to my RingGroup 101

exten => 4,1,Dial(SIP/101)

But I got this problem

[2017-11-13 04:42:31] VERBOSE[3349][C-00000049] pbx.c: Executing [[email protected]:1] Dial("SIP/Trong_Trunk-00000094", "SIP/101") in new stack
[2017-11-13 04:42:31] WARNING[3349][C-00000049] chan_sip.c: Purely numeric hostname (101), and not a peer--rejecting!
[2017-11-13 04:42:31] WARNING[3349][C-00000049] app_dial.c: Unable to create channel of type 'SIP' (cause 20 - Subscriber absent)
[2017-11-13 04:42:31] VERBOSE[3349][C-00000049] app_dial.c: Everyone is busy/congested at this time (1:0/0/1)
[2017-11-13 04:42:31] VERBOSE[3349][C-00000049] pbx.c: Auto fallthrough, channel 'SIP/Trong_Trunk-00000094' status is 'CHANUNAVAIL'

Please, help me to solve this. Thanks you guys!

Use Originate maybe?

Ring groups have no tech. So declaring sip breaks it. Instead you want a goto to goto context from-internal extension 101

How can I do that? Can you show me some example? Thanks you!

Oh, I find out this command

exten => 2,1,Dial(Local/[email protected])

and it work!
Thanks all!

You are now dialing a local channel. Which will cause other issues. You need to be using goto like I mentioned originally.

Can you explain it, give me some more example please, I’m newbie in this.
And in case I want to Dial Out a list PhoneNumber, what should I do?