The Checkout map and the Thank you and Order status map integrations need a Google Maps API key to display the interactive map. You need to request an API key from Google — here's how:
How to get a Google Maps API key
Open the Google Cloud Console (https://console.cloud.google.com/) and sign in to your Google account.
In the left-hand menu, select Billing and provide a payment method (credit card) along with your billing details.
Click the project selector in the top bar, then choose New Project and give the project a name.
From the left-hand menu, under APIs & Services, select Library.
Open and enable the following APIs: Maps JavaScript API, Places API, Roads API.
From the left-hand menu, under APIs & Services, select Credentials.
Click + Create Credentials in the top right, and choose the API key option.
If you already have a Google Maps API key, you can easily activate the thank-you page integration using the Adding the map to the Thank you and Order status pages article, or our checkout page map solution using the Enabling the map on the Checkout page article.