Google Map JavaScript Key is for Google Autocomplete(Suggestion box) and Map.

Follow below steps to create Google JavaScript Key,

1. Go to Google API Console Page, https://console.developers.google.com

2. Create or Select Project.

3. Enable Google Maps JavaScript API in Library page.

4. On the Credentials page, get an API key (and set the API key restrictions).
Note: If you have an existing unrestricted API key, or a key with browser restrictions, you may use that key.