Using nonce from WordPress plugin in JavaScript file

secure-plugin.js

jQuery(document).ready(function($) {
	$.ajax({
		url: ajaxurl, // WP variable, contains URL pointing to admin-ajax.php
		type: 'POST',
		data: {
			'action':'get_custom_data',
			'_ajax_nonce':plugin_ajax_object.nonce,
			'user_data':'Some input from a user'
		},
		success: function( response ) {
			// Here we do what happens if all is good - update the interface with a success message!?
		},
		error: function( response ) {
		   // Whooops, something went wrong!
		   // console.log(response);
		}
	});
});