attempt

functions/src/index.ts

@@ -0,0 +1,10 @@
+import * as functions from 'firebase-functions';
+import * as cor from 'cors';
+
+const cors = cor({origin: true});
+
+exports.helloWorld = functions.https.onRequest((req, res) => {
+    return cors(req, res, () => {
+        res.status(200).send('Hello World!');
+    });
+});