Cannot use Meetings APIs in developer sandbox account

Like a few others that have posted to the forum, I have found I cannot use Meetings APIs with a sandbox account, making it problematic to perform development and, later, to exercise these APIs in order to graduate my app.

In these threads:

https://forums.developers.ringcentral.com/questions/1183/cannot-create-meetings-in-developer-sandbox-accoun.html

https://forums.developers.ringcentral.com/questions/7925/in-order-to-call-this-api-endpoint-user-needs-to-h-3.html

Someone from RingCentral has been able to add Meetings to the sandbox user. @Phong Vu if you or someone else could do this for me, I would be eternally grateful. I am a paid user, not just a free developer account.