The sharing permissions of the Google Spreadsheet should be either “Public” or set to “Anyone with link can view” for the app to fetch cells from the Google Spreadsheet without authentication.
You will also need to publish the sheet (File -> Publish to the web -> Publish) for the data to be accessible from your website or REST powered web app.
Required parameters
gsheet
The ID of the Google Sheet that holds the map data
coloron
Tells the sheet which column to use to color in the county. You only need to use one of the columns. Options include Color, Value, and Category
Optional parameters
states
comma delimited list of state abbreviations that you want the map to focus on
limitstates
disables any states not listed in the states list and hides the county outlines
legend
Positions the legend on the page. Options include: top,bottom,left,right,top_left,top_right,bottom_right,hidden