Force Google Flights to use USD

google-flights-default-USD.js

// ==UserScript==
// @name         Google Flights Default USD
// @version      0.1
// @description  Force Google Flights to use USD
// @author       Kenneth Ballenegger
// @match        https://www.google.com/flights/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=kswizz.com
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    // Get the current URL and parse it
    const currentUrl = new URL(window.location.href);

    // Check if the `curr` URL parameter is present
    if (!currentUrl.searchParams.has('curr')) {
        // If not, add it to the URL
        currentUrl.searchParams.set('curr', 'USD');

        // Replace the current URL with the updated one
        window.history.replaceState(null, null, currentUrl.toString());
        location.reload();
    }
})();