This is experimental and not officially supported by Cloudinary

• Install as a dependency

yarn add nextauth-cloudinary-provider
# or
npm install nextauth-cloudinary-provider

• Add as a provider in /pages/api/auth/[...nextauth].js with your configured credentials

import { Cloudinary } from 'nextauth-cloudinary-provider';

...

providers: [
  Cloudinary({
    clientId: process.env.CLOUDINARY_CLIENT_ID,
    clientSecret: process.env.CLOUDINARY_CLIENT_SECRET,
  }),
]

Read more about how you can use NextAuth.js over at next-auth.js.org.