The places behind the photographs.

Google Maps needs a browser API key, billing, and the Maps JavaScript API enabled in the same Google Cloud project. Restrict the key to Websites / HTTP referrers and restrict its APIs to Maps JavaScript API; never use an OAuth client ID or service-account key here.

1. Create or open a browser key.
2. Add your local and production domains to the website restriction.
3. Enable Maps JavaScript API, attach billing, and set a quota alert.

The page can confirm that Google accepted the key by loading a map, but it cannot inspect your Cloud project, billing, quota, or referrer settings. A failed load is shown below with the next likely action.

Browser key storage is local to this device and is never committed to the repository.