Trying to display total sale value(year-wise and month-wise) in separate scorecards in odoo 16 dashboard module. While checking the base code for demo, they had done it via JSON file.

I have copied the JSON code and tried to accomplish the task but only the scorecard was shown but no data were display because i don't know how to fetch and display the data in the scorecard. I want to know how to fetch the total sale value and how to display it in a scorecard via JSON file.