TI ORDER API: ERR-TICOM-ORDER-API-0009, Aprove error

I managed to create a first test order. The response was basically ok (finding and quoting the correct shipping and billing address), but had the following error:

"errors": [
    {
      "errorCode": "ERR-TICOM-ORDER-API-0009",
      "type": "Validation",
      "section": "Generic",
      "field": null,
      "reason": "Invalid Apruve payment Id",
      "message": "Check your Apruve Account information in checkout profile and resubmit your request. For additional information refer to https://api-portal.ti.com/order-api-payment",
      "data": null
    }
  ]


My Approve account looks properly configured and is added to Checkout profiles. How to solve this problem?

**Attention** This is a public forum