Thank you very much for submitting a support ticket.
Please note that sometimes the free plan on Firebase may not receive messages, and it only provides around 6 SMS messages for testing purposes. To ensure you can receive OTPs reliably, you will need to upgrade your SMS plan on Firebase.
You can follow this link to choose a suitable plan:
https://firebase.google.com/pricing
Make sure you have followed all the steps mentioned in the documentation. If any steps are missed, the feature may not work properly, so please keep that in mind.
after upgrade sms plan, you not receive then please share a error screenshot of debugconsole on VScode or android studio..
Thanks