When I want to approve new recurring payment in PayPal, I got a total amount of 0

I'm trying to test setting up a new recurring payment in the PayPal sandbox. Endpoint for this request is: https://api.sandbox.paypal.com/v1/billing/subscriptions

Body:

{
      "plan_id": "P-9JP75835703395314MA2P3FQ",
      "start_time": "2021-03-04T20:00:00Z",
      "subscriber": {
        "name": {
          "given_name": "John",
          "surname": "Doe"
        },
        "email_address": "[email protected]"
      },
      "application_context": {
        "brand_name": "example",
        "locale": "en-US",
        "shipping_preference": "SET_PROVIDED_ADDRESS",
        "user_action": "SUBSCRIBE_NOW",
        "payment_method": {
          "payer_selected": "PAYPAL",
          "payee_preferred": "IMMEDIATE_PAYMENT_REQUIRED"
        },
        "return_url": "https://example.com/returnUrl",
        "cancel_url": "https://example.com/cancelUrl"
      }
}

When I want to approve newly created subscription, I got this: PayPal approve screen

My question is: why is the total amount 0 (seen next to the cart icon), when the recurring amount is set at 100 PLN?

Solution

If you want it to bill right away, don't specify a start_time