title: Twilio Appointment Reminder tracking Incoming SMS
body: <p>Trying to build appointment reminder using Twilio SMS in .net core. The problem is that a phone number could be associated with more than one user and a user can have multiple appointments in a day.</p>
  <p>Is there anyway to associate an incoming sms either to webhook or studio to a particular ID?
  For example after a appointment reminder is sent through twilio, grab the sid through callback url and then a user confirms or cancels the appointment message, then look at the incoming sid and match it with the send sid?</p>
  <p>is there any alternative to this? other than sending url to the user.</p>
  <p>Thank you all.</p>