Smiirl Custom counter JSON API EPOSNOW

I have purchased a Smiirl custom counter that i would like to show the revenue for 6 retail stores on an epos now systems. Details from smiirl as below; The custom counter set-up is very simple; however, it does require the help of a developer (or someone who knows programming). In order for the counter to display a number that corresponds to the data of your choice, you’ll need to host a JSON* page that stores the data to be displayed. *JSON is a predefined format that allows you to host data in a language that the custom counter can interpret. Here is an example of a JSON page: [login to view URL]: displays “1” The JSON page is the intermediary between the custom counter and the data you want to display. For example, if you want to display your number of users on your custom counter, you must create a JSON page that retrieves and stores your total number of users. Then you enter the URL of your JSON page in your [login to view URL] account so that it can display the number.