Get json data via knime ap and save to file as json file

I would like to build a data extraction automation using POST request and save the data into a json file. I’m using Talend API tester in extracting the data from the endpoint. Need to set the header content-type (application/json) and body text (json format) for username and password. Hope there are examples that are alike to the requirements of the end-point.

Looking forward to your response.

Thank you.