Variable not refresh a DASHBOARD using JSON API

Good morning, I use the JSON API plugin to fetch data from an API and set up a panel with STAT, in this case there are 3 panels, I need to reduce the amount of request in the API, because today each panel makes a request, how can I proceed? I use 2 variables to send the start date and end date of the data, however, with each change in the variable the dashboard sends a request to API.