We could not send your message because this number you're sending from is still being configured. Twilio has received your request to register or deregister this number under a US A2P campaign, but has not completed the necessary configurations with ecosystem partners ("Number Registration"). You will not be able to send messages on the A2P routes until your number status is changed to "Registered".
Twilio is still processing your Number Registration requests with ecosystem partners for US A2P 10DLC
While Number Registration often completes within minutes, under certain circumstances, registration time can widely fluctuate depending on the volume of registration requests. Twilio has received your Number Registration request and is working on configuring your number with ecosystem partners. Please check the status of your number in the Twilio console. You will only be able to send messages on numbers that are in the "Registered" status. To get your number registered, please check out A2P 10DLC Number Registration Best Practices.
NOTE: Users of multiple phone numbers should note that antiquated phone number practices to improve deliverability, such as using multiple numbers to increase throughput or rotating them between their customers or use cases, undermine the deliverability benefits of A2P 10DLC and can lead to processing delays related to 30035 errors. We recommend reviewing A2P 10DLC Number Registration Best Practices.