Create an API key. Set Application restrictions → HTTP referrers to the site you'll host this on.
Paste it below, or hardcode it in CONFIG.apiKey at the top of the script.
Accuracy note: a "no-website" lead means no site is linked on the Google listing. Some will actually have a site Google doesn't know about, or be social-only — glance at "Open in Google" before pitching. Cost: 1,000 requests/month free, then $0.035 each. Email isn't available from Google — leads are name + phone + address.