Making application production credentials for extensions as admin

Hi Eddie. 

Application Key and Application Secret are for the application and not the extensions. Take a look at this post to get started on the sandbox environment :

https://devcommunity.ringcentral.com/ringcentraldev/topics/setup-in-the-sandbox-environment

In order to move the application to Production access we ( our teams ) have certain criterion's which the applications should meet. You could take a look at it here:

https://devcommunity.ringcentral.com/ringcentraldev/topics/production-access-request-criteria

Once the application has been moved to Production you would be able to use the Production Environment Credentials on your application.