Before being able to use Advanced Google Map widget in Elementor, you need to add a Google Map API Key to your website. To learn how to get an API Key from google website you can refer to this link.
Beware: Advanced Map widget is a part of the Jet Elements in Elementor. Jet Elements is a plugin which represents new useful elements to Elementor.
To add an API Key for google map in Elemenor:
1. From the WordPress left dashboard menu, go to Elementor > Jet Elements settings.
2. Click on Google Map Options and paste the API Key you've received from Google API Console.
3. Save the settings. Now you can use Advanced Google Maps widget in your Elementor layout.