How to Fix This:

1. Obtain a valid Google Maps API key from the Google Cloud Console.
2. Ensure the API key is enabled for the "Maps JavaScript API".
3. Create a file named .env.local in the root of your project (if it doesn't already exist).
4. Add your API key to the .env.local file as shown below:

NEXT_PUBLIC_GOOGLE_MAPS_API_KEY="YOUR_API_KEY_HERE"

After adding the key, you will need to restart the development server for the change to take effect.