SERVICE_UNAVAILABLE Error when fetching products. An internal error occurred. Revenue Cat

I’ve properly installed RevenueCat in Flutter and connected Play Store. I’m still getting these error.

Did anyone had this problem? Did you manage to solve it?

Here an error that I get.

API request started: GET /subscribers/appUserID/offerings
D/[Purchases] - DEBUG(11357): API request completed with status: GET /subscribers/appUserID/offerings 304
D/[Purchases] - DEBUG(11357): ℹ️ Requesting products from the store with identifiers: plus_3_card_slots
W/BillingClient(11357): getSkuDetails() failed for queryProductDetailsAsync. Response code: 2
E/[Purchases] - ERROR(11357): 🤖‼️ Error when fetching products DebugMessage: An internal error occurred.. ErrorCode: SERVICE_UNAVAILABLE.
E/[Purchases] - ERROR(11357): 🤖‼️ PurchasesError(code=StoreProblemError, underlyingErrorMessage=Error when fetching products. DebugMessage: An internal error occurred.. ErrorCode: SERVICE_UNAVAILABLE., message='There was a problem with the store.')
E/[Purchases] - ERROR(11357): 🤖‼️ Error fetching offerings - PurchasesError(code=StoreProblemError, underlyingErrorMessage=Error when fetching products. DebugMessage: An internal error occurred.. ErrorCode: SERVICE_UNAVAILABLE., message='There was a problem with the store.')

My app is published on Google Play.
I have created one time purchase at Google Play.
Created offers, entitelments, products at Revenue Cat.
Added billing permission.
Test on real device.

<uses-permission android:name="com.android.vending.BILLING"/>

Solution

To resolve this problem I made 3 steps:

Checked if test device has a PIN. Checked if test device is logged into Google Play Store. Install the app from the internal testing on Google Play, then made a test purchase. Then it started work.

That's all.