How do I enable Google review the premium features of my subscription app?

I have an app and want to start a Closed Testing track to get a review from Google. My app has the following user "roadmap":

1. User initially enters the app, and is required to Sign-up (manual sign-up or one tap sign-in with google).
2. Then, after user account is created, they are directed to Onboarding where they are asked multiple questions.
3. When Onboarding is completed, user is directed to the "Main" app, where they can access all free features of the app.
4. If they want to access premium features, they have to pay for a subscription.

At any time they can log-out and log-in again. In log-in they will be directed to the "Main" app (and not the Onboarding obviously) and have access to the features that correspond to free or premium account.

This is a fairly regular model that multiple apps have. I cant find clear instructions from google, or any other source, on how to submit such an app for review. There are various cases for google testers to check:

1. Completely new user (should I provide them with a testing account?)
2. User sings-up with Google One Tap method (should I create a google account and provide them with it?
3. User has completed Onboarding but is on the Free tier. (testing account?)
4. User has premium subscription (this is my main concern - how do I enable them to access my app? Should I create a base plan with free trial, and enable a test account to be in this plan and then provide the credentials to google? Should I create a promo code and give it to them? What is the standard procedure for such a thing?)
5. How does google test the "Delete Account" feature? Should I create a test account for that as well? Should this account be on the Free Tier or Premium Tier, or Both?

I have already created a username and password, and passed them in App Content -> App Access, but this is just for logging into the app, not for premium access.

Thanks in advance.

Just answering this for anyone interested.

I created 2 user accounts for google to test with:

1. google-premium-test@foo.com
2. google-free-test@foo.com

With the premium account, I completed the onboarding process, entered the app, test-bought a premium account and gave it premium access forever. In my case I am using RevenueCat so I used the "granted entitlements" feature. With this account the google testers can test all premium features.

With the free account, I just signed up, and DID NOT complete the onboarding process so that google testers can test it themselves, and then enter in the free tier of the app, so that they can test it as well.

In both of the accounts, I provided google with the emails, and passwords for each account in:

Play Console / App / App Content / App Access.

I submitted the app for review in the Closed Testing Track. It took them 2 weeks to review my app. The update was accepted.