This  means we're getting this response from Goolge servers, which means there's a problem with your API Key. 

Solution: Create a new API KEY. 

Step 1:  Open the Google Services page.
Step 2. Enter your App name or choose it from the list, then enter any package name for example any.test and finally click on Continue:

Step 3:  Click on Enable Google cloud messaging

Step 4:  Finally copy the API key and Sender ID. 

Step 5: Go to your PushBots dashboard in app settings, and update your Chrome API KEY 

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