> **Description:** Common questions and answers about the Order Management API, including troubleshooting tips, implementation best practices, and clarifications about key features and functionalities.

# Frequently asked questions

Here are the Order Management API FAQs.
See the
[Order Management API guide](https://developer.vippsmobilepay.com/docs/APIs/order-management-api/order-management-api-guide.md)
for all the details.

## Can I combine different `category` types?

No, a payment can only have one `category`.
When you do a
[`PUT:/order-management/v2/{paymentType}/categories/{orderId}`](https://developer.vippsmobilepay.com/redocusaurus/order_management-swagger-id.yaml)
it will replace an existing `category`.

## Can I update `orderLines` for a payment?

No, not yet. It is only possible to do
[`POST:/order-management/v2/{paymentType}/receipts/{orderId}`](https://developer.vippsmobilepay.com/redocusaurus/order_management-swagger-id.yaml)
once.

This is a known limitation, and we will update here if this changes.

> **Full site overview:** For every page in this documentation, read [https://developer.vippsmobilepay.com/llms.txt](https://developer.vippsmobilepay.com/llms.txt).