Example usage of auto swith url, set username, save token

postman-scripting.js

// prerequest script
// hooked before call
if (pm.environment.get("offline")=="on"){  
    pm.environment.set("baseURL", pm.environment.get("offlineSite"));
}else{ 
    pm.environment.set("baseURL", pm.environment.get("onlineSite"));
}
    
    
pm.environment.set("username", "salt");
pm.environment.set("password", "salt");


//  test script
// hooked after call
var jsonData = pm.response.json();
postman.setEnvironmentVariable("token", jsonData.msg);