1. Error

https://next-auth.js.org/errors#get_authorization_url_error client_id is required {
  message: 'client_id is required',

2. Error message is unkind

client_id -> clientId

3. Cause
Because clientId is not set in [ …nexauth.ts]

4. Check value of clientId

  providers: [
    GithubProvider({
      clientId: process.env.GITHUB_CLIENT_ID,
      clientSecret: process.env.GITHUB_CLIENT_SECRET,
    }),

    GoogleProvider({
      clientId: process.env.GOOGLE_CLIENT_ID,
      clientSecret: process.env.GOOGLE_CLIENT_SECRET,
    }),

  ],