Even if not required, it's good practice to request and use an API key to display maps inside Domus Organizer. Some customers reported that if such key is missing, Google won't load the map. To be on the safe side, always create and store it in your site.
You can find the steps to create it inside Google documentation, however we reported them here for simplicity:
Connect to console.developers.google.com
In the upper right navigation bar select Create new project
Choose a name for your project
In the Overview page of your project, click on Google Maps Javascript API and then on the Enable button
Then go in the Credentials tab and click on Create Credentials. Select the API key type
Click on the Browser key button
Choose a name for your API key
Congratulations! You're done! You can use the new API key inside Domus Organizer Component options
