Google maps

Why do I get the message that the Google Maps API key cannot be used?
The message 'API keys with referer restrictions can not be used with this API' comes up when there are restrictions on the api key. Since we use the serverside geocoder this is not allowed. So the advice is not to put any restrictions on the set api key. For more information go to one of the following pages :
-https://developers.google.com/maps/documentation/embed/get-api-key#creating-api-keys
-https://developers.google.com/maps/api-key-best-practices#:~:text=You%20can%20restrict%20an%20API,platforms%20(Android%20and%20iOS)
-https://developers.google.com/maps/api-key-best-practices#api_key_table