When you're using GET method and trying to input data, the JSON data has to be encoded like below:
%7B%22operation%22%3A%7B%22details%22%3A%7B%22from%22%3A%220%22%2C%22limit%22%3A%2250%22%2C%22filterby%22%3A%22All_Requests%22%7D%7D%7D
The same can be done for Postman as well where you can include the format as Json, followed by INPUT_DATA