Which Google API is required?

[WeeSee]

I created a key from Embed Maps API and the extension didn't work.

There is a console browser message that displays an error from Google: NO_API-KEY

What Google API Key is required exactely?

Since I need maps view in a closed web app I want to know if the API usage is free of charge for few requests (in february of 2020)?

[namgee]

You need to create an API key from Google Maps, and use the generated API from Google Maps Console section.