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Mutiple Areas Select in choropleth mapbox in Dash

Hello All,
I am new to this community and this is my first topic. So excuse me if I make any mistakes. I have searched the community topics to get a solution but couldn’t find any. I have integrated a Mapbox design with Dash. I am working on New York county-level data. As of now, I could only select one county at a time. How can I select multiple counties at a time and how can I restrict the selection of counties to a maximum of 3? Really appreciate your great help if you can provide me a solution for this.