Failed to connect to Adobe Sign

I created a Adobe Sign developer account, and got Application ID and Client Secret.

Then, I went to AEM, Tools > Deployment > CloudServices > Adobe Document Cloud eSignature services. Clicked Configure now,  created eSignDCSS. Then filled  in Client ID and Client Secret fields with the above Application ID and Client Secret values. 

When clicked “connect to Adobe Sign” button, it failed to connect, and message below shows on the screen.

           Your connection is not private

Attackers
might be trying to steal your information from bc-psg (for
example, passwords, messages, or credit cards). Learn more

NET::ERR_CERT_COMMON_NAME_INVALID

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Google to help detect dangerous apps and sites. Privacy policy

Does anyone know what is going on here?  Any tips to make successful connections to Adobe Sign are highly appreciated.