Make sure you are on the new submission process. You can do so here - and from our experience the approval time was almost immediate. You'll know it's working because you'll be able to see the new functionalities in the 'features' section of your ASC dashboard.
First thing's first, make sure you have your assets ready, with Product Page Optimization you can test:
Your app's status must be in 'Ready for Sale' in order for its product page to be tested, and if you submit a new app version while a test is running, the test will automatically stop!
With you activated account, go to your app page in App Store Connect, you'll see the 'In-App Purchases' section has now been replaced with 'Features'. Select 'Product Page Optimization' at the bottom
From this page, select 'Create Test', and you'll open a setup modal with some options:
From here you can see the following options:
Once these options are filled, you can press 'Create Test' to move on to setting up your treatments.
Now you've selected your options and created the test, you'll be taken to your treatment setup page. By default the treatments are duplicated from your original product page
There's some important things to note at this stage:
If you have additional icons in your app binary, you'll be able to see an additional section in the 'assets' screens:
As mentioned, if you have added screenshots or previews to your test, your app will need to go through App Review. If you are just moving metadata around or changing the icons it will not be necessary.
If you had added screenshots or previews you will be told the app is going through App Review:
Once the metadata is accepted by App Review, your Product Page Test will go live.