# About Try it

Learn how to effectively use the Try it feature in the Payments by Booking Onboarding API documentation.
Use the **Try it** feature to send sample requests to API endpoints directly from the developer portal. In the **Mock (schema only)** environment, Try it returns schema-driven mock responses or pre-built example responses. In the **Production** environment, it sends the request to the live API and returns dynamic responses from your selected test property.

 - [Environment](https://developers.booking.com/connectivity/docs/openapispecs/payments-by-booking-onboarding-api/pbb-onboarding-api-specification/about-try-it/environment.md): ## Environment You can select between three different environments (top right corner in the UI): **Mock (schema only)** (default): - Helps to understand the response data schema - Recommended for all
 - [Request](https://developers.booking.com/connectivity/docs/openapispecs/payments-by-booking-onboarding-api/pbb-onboarding-api-specification/about-try-it/request.md): ## Request You can click on any unresolved placeholders to add a value or edit an existing placeholder value. The portal loads the default request and response body. Where the specification supports m
 - [Response](https://developers.booking.com/connectivity/docs/openapispecs/payments-by-booking-onboarding-api/pbb-onboarding-api-specification/about-try-it/response.md): ## Response After executing a request, you will see: - **Status code**: HTTP response status - **Response body**: JSON response data - **Headers**: Response headers
 - [Simulating error responses](https://developers.booking.com/connectivity/docs/openapispecs/payments-by-booking-onboarding-api/pbb-onboarding-api-specification/about-try-it/simulating-error-responses.md): ## Simulating error responses When using the **Mock (stateful simulator)** environment, you can simulate authentication and server error responses by setting specific values in the `Authorization` hea
 - [Common issues](https://developers.booking.com/connectivity/docs/openapispecs/payments-by-booking-onboarding-api/pbb-onboarding-api-specification/about-try-it/common-issues.md): ## Common issues - **401 Unauthorized**: Check your credentials - **403 Forbidden**: Verify access permissions - **404 Not Found**: Confirm the request ID exists (status endpoint only) - **429 Too Man