If you see the error when installing the module: file was encoded by the ionCube Encoder for PHP 5.6 and cannot run under PHP 7.1 or later

Try to uninstall the module and install it for php 7.2 version from the link

https://calltrix.ru/repo/calltrix7.zip

In the “Destination” field, you must specify the call route in case if Calltrix cannot identify the responsible user, or the application expires, or Bitrix24 is unavailable and the database does not contain information about caller number.
In other words, this is the route that is used in case of failure, as you can see in the help section near (if you hover over the question mark).
If you specify Calltrix, the route will be looped back and you will see an error.

Usually there a secretary or a ring group, which receives calls from unknown clients.