[Rest API] PlayStore: POST `/v1/receipt` and base plans

Hi there!

We have one subscription subscription_id, within which there are two base plans base_plan_id_1 and base_plan_id_2.

After purchasing, our application sends a fetch token to our server, which we forward to /v1/receipt/:

{
  "app_user_id": "$someUserId",
  "fetch_token": "$someValidFetchToken",
  "is_restore": false,
  "product_id":  "subscription_id"
}

The call is executed successfully, but in RevCat and all webhook events, it always shows that the base plan base_plan_id_1 was purchased, regardless of which actual base plan was bought.

Example:

• User buys a Monthly subscription for 0.99 - it works and is tracked correctly
• User buys a Yearly subscription for 9.99 - it’s tracked in RevenueCat as Monthly for the price of 9.99

After studying the SDK, we tried sending the following variants, but nothing changed.

1. Sending platform_product_id:

{
  "app_user_id": "$someUserId",
  "fetch_token": "$someValidFetchToken",
  "is_restore": false,
  "product_ids": [
    "subscription_id"
  ],
  "platform_product_ids": [
    {
      "product_id": "subscription_id",
      "base_plan_id": "base_plan_id_2"
    }
  ]
}

2. Sending platform_product_id and pricing_phases:

{
  "app_user_id": "$someUserId",
  "fetch_token": "$someValidFetchToken",
  "is_restore": false,
  "product_ids": [
    "subscription_id"
  ],
  "platform_product_ids": [
    {
      "product_id": "subscription_id",
      "base_plan_id": "base_plan_id_2"
    }
  ],
  "pricing_phases": [
    {
      "billingPeriod": "P1Y",
      "billingCycleCount": null,
      "recurrenceMode": 1,
      "formattedPrice": "£58.99",
      "priceAmountMicros": "58990000",
      "priceCurrencyCode": "GBP"
    }
  ]
}