In the Javascript above, set the "API_URI" variable to the following:
https://API_Gateway_Invoke_URL/wallboard/?Wallboard=Wallboard_Identifier
Where "API_Gateway_Invoke_URL" is found in the API Gateway console and the "Wallboard_Identifer" is what you've called your dashboard/wallboard in the DynamoDB table. This will have been configured in the YAML template when the dashboard/wallboard was created.
The API returns a formatted HTML table that it places in the "wallboard" div below. Colours for cells are set in the dashboard/wallboard definition and are automatically returned in the table - however, you can choose to use additional styles in the calling HTML page to format the table. For example, you may choose to centre the data in each table cell. This is deliberately done so that customers may display their dashboard/wallboard however they like or can embed it in any HTML page as required. Individual cells have unique classes and labels; within each cell there is a separate div for static text and data. You'll find brief examples of this in the HTML <head> section above.
You may also adjust the refresh interval by changing the "RefreshInterval" variable in the code above.