I uploaded API spec and documentation, but how can I make others call my API so that the number of requests and other data will not be empty here?

@cuican.helen - You need to associate this product to a Service running in Gateway.

This can be done by adding a version to the product (Product Versions).

This could be a public API (with no restriction) or a protected API (with keyauth/openid) with App Registration Enabled

Then you can start sending traffic to the endpoint which will show up here.