Give callers to have the ability to dial another extension i

Asterisk Asterisk Support
1

I would like my callers to have the ability to dial another extension if user does not pick phone up.
How can I do that ?

In my Extensions.conf

exten => 4002,1,Dial(SIP/402,20)
exten => 4002,2,VoiceMail(402@VoiceMail)
exten => 4002,3,VoiceMail()
2

if user does not pick phone up, send the caller to a Disa() app.

3

Or WaitExten, if they don’t need any more privilege than they had for the initial call.