Create custom db table and fields from plugin

Dev
4

Assuming I create a method within my plugin.rb file to set these values programmatically how could I access them through an xhr request?

Is there a way to expose internal plugin methods to the outside world?

For example something like

//plugin.rb file contents
def update_fields
//Save fields
end

//plugin.js contents

            Discourse.ajax("plugin#update_fields", {
              type: 'POST',
              dataType: 'json',
              data: {#}
            }).then(function(json) { //On success
            
             }, function(json) { //On error

            });