API keys with referer restrictions cannot be used with this API. When you set the referrer for the server key to the domain name instead of the IP address, then it will show this message. To fix this change the restriction from 'HTTP referrers' to 'IP Address' for the server key.

Ensure that your public and private keys are entered in their correct fields. There are instances where a public key was used instead of a private key, and vice-versa. One pair of API keys won't work on multiple sites. If you have multiple sites, make sure each site has the correct pair of API keys.

Double-click the saved HTML file to open it in your web browser. To access developer tools, right-click anywhere on the page and select "Inspect" or "Inspect Element" to open the browser's developer tools. Navigate to the "Console" tab. Here, you will find any errors or messages related to your API key.

Steps to fix the RefererNotAllowedMapError Click the hamburger menu and select APIs & Services > Credentials. Click the name of the API key that you want to modify. Click the Edit button in the restriction section > In the Key Restrictions section, select the Websites referrers option.