1. In your FreePBX, SRV Lookup should be enabled:
Do so under the "Settings" tab, under "Asterisk SIP Settings" - "Advanced General Settings"
2. Under "Connectivity" - "Trunks" add SIP trunk.
Enter the following information:
111111: Your sip number from personal account
Password: Your sip number password from "SIP-settings" in personal account.
Trunk Name: Zadarma
USER Context: 111111
Register String: 111111:firstname.lastname@example.org/111111
In PEER Details and USER Details enter the following data:
3. Under "Connectivity" - "Inbound Routes" create an inbound route Zadarma-in
DID Number: 111111
Under "Set Destination" you can set where the call will be routed to (a FreePBX internal number, a call group, IVR, etc.)
4. Under "Connectivity" - "Outbound Routes" create an outbound route Zadarma-out.
Under "Dial Patterns that will use this Route", in the blank space indicated as "match pattern", enter a point (.) This is indicated by a red arrow in the following screenshot) and create a route. If you skip this stage, you will not be able to make outgoing calls.