Here is how your IAX config file(s) should look.

You should forward your FlyNumber using the "VOIP" option and use your Asterisk IP in the
"Host" .

[46.19.209.10]
type=friend
host=46.19.209.10
trunk=yes
context=from-fly
qualify=no
canreinvite=no
dtmf=rfc2833
 
[46.19.209.11]
type=friend
host=46.19.209.11
trunk=yes
context=from-fly
qualify=no
canreinvite=no
dtmf=rfc2833
 
[46.19.209.12]
type=friend
host=46.19.209.12
trunk=yes
context=from-fly
qualify=no
canreinvite=no
dtmf=rfc2833
 
[46.19.209.13]
type=friend
host=46.19.209.13
trunk=yes
context=from-fly
qualify=no
canreinvite=no
dtmf=rfc2833
 
[46.19.209.14]
type=friend
host=46.19.209.14
trunk=yes
context=from-fly
qualify=no
canreinvite=no
dtmf=rfc2833
 
[46.19.209.15]
type=friend
host=46.19.209.15
trunk=yes
context=from-fly
qualify=no
canreinvite=no
dtmf=rfc2833
 
[46.19.209.75]
type=friend
host=46.19.209.75
trunk=yes
context=from-fly
qualify=no
canreinvite=no
dtmf=rfc2833
 
[46.19.209.76]
type=friend
host=46.19.209.76
trunk=yes
context=from-fly
qualify=no
canreinvite=no
dtmf=rfc2833
 
[46.19.209.77]
type=friend
host=46.19.209.77
trunk=yes
context=from-fly
qualify=no
canreinvite=no
dtmf=rfc2833
 
[46.19.209.78]
type=friend
host=46.19.209.78
trunk=yes
context=from-fly
qualify=no
canreinvite=no
dtmf=rfc2833
 
[46.19.209.79]
type=friend
host=46.19.209.79
trunk=yes
context=from-fly
qualify=no
canreinvite=no
dtmf=rfc2833
 
[46.19.209.80]
type=friend
host=46.19.209.80
trunk=yes
context=from-fly
qualify=no
canreinvite=no
dtmf=rfc2833
 
 
Under 'iax_general_custom.conf.' add following lines: 
requirecalltoken=no
calltokenoptional = 46.19.209.0/255.255.255.0