Hey Peter,
Seeing that you’re getting a daily quota exceeded error, could you please check that your translate API Characters per day quota is a non-zero value. You can find this information by clicking on the Google Translation API found on the API Dashboard. Once in the Translation API dashboard, you will find the information pertaining to your Characters per day limit under the Quota tab on the left hand side of the page .
If the quota is indicated to be 0 and can not be modified, there might be some issue with your billing.