Trunk SIP help

Hello
I am conducting my PAP (which is based on creating a VoIP server)
and I am using Asterisk for this, but I encountered a problem when I tried to configure the SIP trunk, because I am ZON customer and they do not provide this service, so I installed “VoIP Buster” and wonder how I can configure the SIP Trunk using the account created in VoIP Buster.

I hope someone can help me.

This are the configurations I have:

Peer Details

Trunk Name: VoipBuster
disallow=all
allow=alaw&ulaw&gsm
context=from=pstn
dtmfmode=inband
fromdomain=sip1.voipbuster.com
fromuser=
host=sip1.voipbuster.com
insecure=very
nat=yes
qualify=yes
secret=
srvlookup=yes
type=friend
username=

Register String:
:@sip1.voipbuster.com/