Alias is already configured through the project settings.

ghengeveld · ghengeveld · commit e76564840dfa · 2019-09-17T13:52:04.000+02:00
diff --git a/now.json b/now.json
@@ -1,7 +1,6 @@
 {
   "version": 2,
   "name": "react-async",
-  "alias": "react-async.now.sh",
   "public": true,
   "builds": [
     {
