feat(external-api) Expose meeting session (#14522)

modules/API/external/external_api.js

@@ -1229,6 +1229,17 @@ export default class JitsiMeetExternalAPI extends EventEmitter {
         return this._numberOfParticipants;
     }
 
+    /**
+     * Return the conference`s sessionId.
+     *
+     * @returns {Promise} - Resolves with the conference`s sessionId.
+     */
+    getSessionId() {
+        return this._transport.sendRequest({
+            name: 'session-id'
+        });
+    }
+
     /**
      * Returns array of commands supported by executeCommand().
      *