In order to assign a phone number to one of your Call Flows, you have two options.
1- Head over to your 'Phone Numbers' page under 'My Settings'
2- Find the number that you want to assign to your Call Flow, and select it from the drop down menu:
Once the Number is assigned to the Call Flow, whenever a call comes in to that number, it will follow any Call Routing you have configured on that Call Flow.
1- Go to the Call Flow that you want to assign your Phone Number to (in our example, it's named 'Sales')
2- On the 'Phone Number(s)' section, click on 'Choose Existing':
3- Select the phone number (or numbers) that you want to assign to this Call Flow, and hit 'Save' when done.