How to make call handling of a specific user through a specific trunk in Asterisk?

Question

Asterisk

In the sip.conf file, I have a user who registers his softphone and makes calls. He only needs to make outgoing calls. Further in the same file, the trunk is described through which you want to make calls. The issue is that on this server with Asterisk there are already a bunch of users who make calls through completely different trunks, and there is no idea how to describe this whole miracle in extensions.conf.
Brief extract from configs:
sip. conf

[manager-phone](!)
type=friend
context=ManagerCalls
host=dynamic
secret=
nat=force_rport,comedia
disallow=all
allow=ulaw
allow=alaw
callerid=

[TESTING1](manager-phone)
[TESTING2](manager-phone)
[TESTING3](manager-phone)

[out1]
type=peer
qualify=7000
insecure=invite
host=
port=
username=
fromuser=
fromdomain=
secret=
context=IncomingCalls
disallow=all
allow=alaw,ulaw

[out2]
type=peer
qualify=7000
insecure=invite
host=
port=
username=
fromuser=
fromdomain=
secret=
context=IncomingCalls
disallow=all
allow=alaw,ulaw

extensions.conf

[OutOut1]
exten => _X.,1,NoOp(OutProvider:out1)
    same => n,Dial(SIP/out1/${EXTEN},60,T)
    same => n,Hangup()

Those. need user TESTING3 to call through out2 line

Answer 1

exten => _X./TESTING3,1,Dial(SIP/out2/${EXTEN},60,T)