Hi Krishna,

Yes, you can consume REST API in reactive web apps and it is done same as we do it for other application types. You should go through the web service class and integrtion master class to understand it in details

https://www.outsystems.com/learn/lesson/870/web-services

https://www.outsystems.com/learn/courses/116/integrating-with-web-services/

After creating access to the API according to the lessons mentioned above. You can follow this tutorial to learn how to use a DataAction.

https://www.outsystems.com/learn/lesson/1947/displaying-data-on-screens 

At DataAction you can consume Api.

The most important details in this text are the steps needed to consume an external REST API in reactive web development. These steps include determining the API endpoints, using asynchronous requests, handling HTTP responses, handling error handling, including authentication and authorization, applying best practices, testing and validating the integration, and considering API documentation. These steps will help ensure that the integration works as expected and that the data and functionalities of the external REST API are utilized within the application. Additionally, it is important to follow best practices such as using appropriate HTTP methods for different operations, adhering to RESTful principles, handling pagination if applicable, and considering caching mechanisms to optimize performance. Finally, it is important to adhere to the API provider's guidelines to maintain a smooth and compliant integration. As someone who is involved in this Affordable web designing services  for many years, I would like to refer , It not only focused on discussing the topic inside out but also Benefits.