The website/company seems to be located in Bengaluru, India so I doubt HIPAA applies to them.

https://cloud.google.com/security/compliance/hipaa/identity-... - looks like, at least for Cloud Identity (for employees accessing the internal records and databases themselves) - it's HIPPA compliant when the people implementing it do their DD. Since GSuite and Gmail logins are fairly tightly integrated, I would bet the regular auth system and oauth system for Google accounts is HIPPA-complaint.

If you are using a service like google oauth you need to sign a business associate agreement with them before using any of their services in a HIPAA compliant manner. I've searched for how to sign this contract pretty unsuccessfully.