Many factors can prevent you of seeing data in your dashboard when integrating your product with callstats.io for the first time.
As a first step we recommend to verify if requests to callstats.io servers are sent via HTTP2 instead of HTTP1. If your app is browser based, modern browsers should support the use of HTTP2, but still can have some issues.
You can find more information about the issues related to HTTP1 support in this article
Do you still have issues?. Please contact firstname.lastname@example.org for further assistance.