You can create TwiML Apps to be used with your custom Twilio applications on the Create TwiML App page in the console. You may also use the Applications API to programmatically create one. We'll walk you through the steps to create a TwiML App in the console.
Each TwiML App can be configured with a friendly name. Each TwiML App also has a Voice Request URL parameter that you can set to your voice application's publicly accessible URL, as well as a Messaging Request URL parameter that can be configured to your messaging application's publicly accessible URL. Don’t forget to click Save once you enter the URLs.
You can view and edit your TwiML Apps on the TwiML Apps page. This is where you can get your application SID to be used with your custom Twilio Applications.
To associate your Twilio number with a TwiML App, visit the Numbers page. Then Go to the Properties page by clicking on the phone number you wish to configure, and select "Configure with Application." The Request URL field would be replaced with the Application drop down. Select the friendly name of the application you set up and then save your change.
You may also associate a TwiML App with your phone numbers by setting the "VoiceApplicationSid" using the Incoming Phone Numbers API.