https://www.telerik.com/blogs/how-to-implement-google-authentication-nextjs-app-using-nextauth How to Implement Google Authentication in Next with NextAuth This article demonstrates how to incorporate single sign-on using OAuth protocol in a Next.js application via the NextAuth module with Google authentication. www.telerik.com 이 글을 따라하면 잘 됩니다. firebase login을 연동하는 방법이 server기반 (firebase-admin)을..