EngineOptionsBuilderGoogleApiKey Property

public string GoogleApiKey { get; set; }

Property Value

Some Chromium features such as Geolocation, Spelling, Speech, etc. use Google APIs, and to access those APIs, an API Key, OAuth 2.0 client ID, and client secret are required. Setting up API keys is optional. If you do not do it, the specific APIs using Google services won't work.

Reference