Converting backend `pdf-stream` to pdf and save to local system

I am getting a pdf-streat as a response from backend server. I require to convert this stream to pdf file and require to allow the user to save on their local machine. how to do that?

here is the response i receive:

    "pdf-stream": "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",
    "rel-number": "C123441"
},