Update plugins/carbon.js

plugins/carbon.js

@@ -57,6 +57,12 @@ async function MakerCarbon(args) {
  *         description: The code to be processed.
  *         schema:
  *           type: string
+ *       - in: header
+ *         name: x-api-key
+ *         required: true
+ *         description: API key for authentication
+ *         schema:
+ *           type: string
  *     responses:
  *       200:
  *         description: A successfully processed image.