If you have multiple SIP Profiles, be sure to repeat the process on applicable SIP Profiles.
If you choose to create a new routing plan, once the changes is applied, you will be able to find the name of the routing plan in the SIP Profile settings:
Switch over to "Configuration->Routing->SIP Message Routing" and you will find the routing plan, click "edit" to display the contents.
In the routing plan, a condition must exists to match with each SIP Message types that was checked in SIP Profile setting -> "Siprelay allow methods". If you seleted "Create New Plan", the routing plan content will be automatically generated. If you reuse existing routing plan, please make sure condition entrie's "expression" attribute matches with selected message types in "Siprelay allow methods".
In this routing plan, once a message type is matched, "sip_relay" appliaction is launched to route the message to the specified destination. Optionally, header manipulation on the forwarding message can be added before the "sip_relay" application.