Hi @damiengarrido/@shresthasu,
To get raw binary data there is a way in postman by extracting stream of data from pm.response object. You can use below snippet to extract the data and specify the byte stream.
const mark1 = (pm.response);
console.log(mark1.stream.toString('utf-8'));
To convert the byte stream to base64
console.log(btoa(mark1.stream));
Hope it helps