According to Google: This error Indicates that user has exceeded the daily quota (either per project or per view (profile).
You would see a “403 Daily Limit Exceeded” error response when Analytify tries to fetch the data from Google analytics and it hits the daily limit quota. Google analytics has limits on its data per day and per website profile. Remember, Analytify is using its own default API keys.
We highly recommend using your own API keys. So, you don't run into these quota exceeded errors. We have a detailed guide written for creating the Google console project and generating API keys which you can use in the plugin Analytify->settings page at the advanced tab. Simply tick the checkbox and add your details.
Here is a quick video tutorial
If you are still unable to create API keys. We have a paid service to setup API keys for you.