Case
this issue happens when you finish connecting your Twilio account to your Project in Jira Service Management, you text the number and you don't receive a new ticket in Jira.
Reason
The number used in the configuration is the wrong one, the number entered in the configuration page should be the sandbox number. where you set the HTTP POST calls.
Solution
The below steps are for testing purposes, where we are using the test WhatsApp sandbox provided by Twilio
If you have a subscription with Twilio, you can find your number under WhatsApp Senders
Note: If you have a valid WhatsApp phone number the page will appear like below
Go to your sandbox where you set your HTTP POST call and get the phone number of the sandbox.
then go to your project settings and link Twilio account and add the number above in the Twilio phone number then continue with your settings and then text the entered mobile phone and you'll receive a ticket in Jira.