How to add query param to send request url using a pre request script postman?

I would like to be able to add a query param to the pre request script sendRequest url shown below, but havent been able to figure out how to do that.... I have tried to use different options to no avail. Thanks for the help!

pm.sendRequest({
        url: pm.globals.get("base_url") + bankNum + "/loans/" + loan14,
        method: 'GET',
        header: {
        'Authorization': '********',
        },
    }, function (err, response) {
        console.log(response.json());
    });