i understand the problem now. you are displaying CSV data in your webmap, but this is not the same thing as converting CSV data to be a hosted feature service.
please follow the steps in the article i linked to above (called "Publishing a hosted feature service using a shapefile or CSV file"), and add that new data source to your webmap instead of adding the CSV content directly.
hosted feature services are editable from within web applications. dynamically drawn CSV data is not.