Transit calls from SIP trunk to another server

Good afternoon.
I ask for your advice and help. There is such a configuration:
two servers FreePBX, interconnected IAX2 trunk.
IAX settings are:

FREEPBX1
PEER Details:
username=1067
type=peer
secret=welcome
qualify=yes
insecure=port,invite
host=10.10.1.67
allow=gsm,ulaw
disallow=all
canreinvite=no

USER Context: 1068
type=user
secret=welcome
context=from-trunk

FREEPBX2
PEER Details:
username=1068
type=peer
secret=welcome
qualify=yes
insecure=port,invite
host=10.10.1.68
allow=gsm
disallow=all
canreinvite=no

USER Context: 1067
type=user
secret=welcome
context=from-internal

Dialplan 21XX and 41XX.
Internal calls with FreePBX1 to FreePBX2 on call fine.
The server FreePBX2 has two SIP trunk, on SIP provider.
How to set up calls from the server FreePBX1 through SIP trunk is registered to FreePBX2???

Now I do it like this:

Incoming Route

DID Number: _7863XXXXXXX
Set Destination: Trunks - SIP trunks.

But I guess that’s not correct.
Please help! And sorry for the bad english.