Be sure to check out the example application https://github.com/citybaseinc/ex_ari_example
The ARI protocol is a robust interface for controlling Asterisk and reacting to Asterisk events. It has been thoroughly tested with Asterisk versions 15 and 16.
ARI stands for Asterisk REST Interface. Through the REST interface it is possible to control just about every aspect of an Asterisk server. ARI also provides a Websocket interface for consuming events from the Asterisk Server. This library has full support for both the REST and Websocket protocols.
If you’re not to familiar with Asterisk, there’s an example repo that will get you up and running with a custom Asterisk IVR in a few minutes, https://github.com/citybaseinc/ex_ari_example .
The documentation is pretty thorough, but it definitely helps to understand Asterisk and ARI.
Check the docs here, https://hexdocs.pm/ex_ari/readme.html
and on hex.pm https://hex.pm/packages/ex_ari