Hi Rohan,

Follow these links from Outsystems https://success.outsystems.com/Documentation/11/Extensibility_and_Integration/REST

or in more depth https://www.outsystems.com/training/courses/116/integrating-with-web-services/

Hi rohan,

Training Material - https://www.outsystems.com/training/courses/116/integrating-with-web-services/

REST API - https://success.outsystems.com/Documentation/10/Extensibility_and_Integration/REST

Consume REST API - https://success.outsystems.com/Documentation/10/Extensibility_and_Integration/REST/Consume_REST_APIs/Consume_a_REST_API

Expose REST API - https://success.outsystems.com/Documentation/10/Extensibility_and_Integration/REST/Expose_REST_APIs/Expose_a_REST_API

Check REST API Authentication in LifeTime

https://success.outsystems.com/Documentation/11/Reference/OutSystems_APIs/LifeTime_API_v2/REST_API_Authentication

Custom API Advanced customizations

https://success.outsystems.com/Documentation/10/Extensibility_and_Integration/REST/Consume_REST_APIs/Advanced_Customizations

Have you referred to the solution for JSON?

https://www.outsystems.com/forums/discussion/40945/consume-rest-api-and-send-custom-headers-in-onbeforerequest/#Post147822

Refer this post too..

Refer below post

https://www.outsystems.com/forums/discussion/73029/api-expose-consume-add-authentication-using-bearer-token/

Thanks, Aadhavan S