Issue Related to the RingCentral In Salesforce - edition is not Suitable for the Edition

Hi RingCentral Communities, 
Issue : Your Edition does not support for salesforce Integration. please contact your account representative to upgrade your ringcentral edition 

Steps followed : 
1.Logged into RingCentral App 

2. Installed RingCentral for salesforce in Developer edition as well as Sandbox.
3. Completed the whole step up of RingCentral App in Salesforce or (as mention in step 2)
4. When i click on the RingCentral Utility - I am facing issue - The Issue as I mention in the Issue column. 

Could anyone help me how to solve this issue. 

Screenshot of the Issue