Once you have setup the project on Google Cloud, you need to acquire the Key, and place it in Android and iOS projects.
You’ve to put the API key in configuration.json (automatically or manually) as well as in native project files. This API key is used for Maps, Places search and Static Maps.
Setup maps api key by Houzi Config
You can use Houzi Config Builder to save the Maps api key: Theme Api & Config.
Setup maps api key by config.json
You can change colors from config by replacing *** with your own color code. Open the Project_HOME > assests > configuration > configuration.json file, and look for the following keys:
"google_map_api_key": "your_key_here",
Additional steps (mandatory)
After adding maps key in configuration.json, its mandatory to add this in native projects as well. Because both platform use native maps sdk to show maps in flutter apps.
Android
Open AndroidStudio, expand android > app > src > main > res > values project folder, and find strings.xml file in your Android project. And look for the map key map_api_key and paste the key in value attributes.
iOS
Open Xcode and goto AppDelegate.swift, look for GMSServices.provideAPIKey() and paste your key in there.