Method : GET 

URL : https://raw.githubusercontent.com/kjur/jsrsasign/master/jsrsasign-all-min.js

Post Response Script : 

// This saves the library code into a global variable named 'jsrsasign_code'

pm.globals.set("jsrsasign_code", pm.response.text());

// This script runs AFTER the response is received

if (pm.response.code === 200) {

    // pm.response.text() gets the raw library code from the response body

    pm.globals.set("jsrsasign_code", pm.response.text());

    console.log("Library stored successfully!");

}