Ho set a variable in a object Json

Hello everyone, since then I am trying to send a variable to a json object but its pass. I explain. I have an image which I convert to base64 which I want to assign to a variable which will be sent on a json object. on the header I have an api_key that I set its value. when with postman or ARC its progress it returns me as status code 200 but on uipath its progress. please could someone help me?

Hello Abdou,
In this video, I upload a file to Salesforce from UiPath Studio using Conversion ToBase64:

Cristian Negulescu