Not sure if this works, try trigger when PRs are merged into main

.github/workflows/main2prod.yml

@@ -1,9 +1,13 @@
-name: Pull Request to `main` from `production`
+name: Pull Request into `production` from `main`
 
 on:
   push:
     branches:
       - main
+  pull_request:
+    types: [closed]
+    branches:
+      - main
 
 jobs:
   auto-pull-request: