Our plugin, in collaboration with the Twilio platform, is used to send messages, so this is its main purpose. And your idea of using it requires integration with Twilio, which is done through the API Connector.
The message of an error you are getting is not related to our plugin, therefore, unfortunately, we won’t be able to assist, as your use case is not related to our plugin’s functionality or set up and therefore is beyond our support services.
I am really sorry about this.
So, from my side, I can provide you with some sources, which will help you in your case. First, try to check this link with the documentation for the API workflow:
Also here is some of Twilio’s documentation, in case you haven’t go through it yet: