message: 'invalid_client (Client authentication failed)' for LinkedIn Provider

[starbvuks]

here's my /api/auth/[...nextauth]/route.js

import NextAuth, {NextAuthOptions} from "next-auth/next";
import LinkedInProvider from "next-auth/providers/linkedin"

export const authOptions = {
    providers: [
        LinkedInProvider({
            clientId: String(process.env.LINKEDIN_CLIENT_ID),
            clientSecret: String(process.env.LINKEDIN_SECRET_ID),
            authorization: {
                params: {scope: "openid profile email"}
            },
            issuer: "https://www.linkedin.com",
            jwks_endpoint: "https://www.linkedin.com/oauth/openid/jwks",
            profile(profile, tokens) {
              const defaultImage =
                "https://cdn-icons-png.flaticon.com/512/174/174857.png";
              return {
                id: profile.sub,
                name: profile.name,
                email: profile.email,
                image: profile.picture ?? defaultImage,
              };
            },
        })
    ]
}

const handler = NextAuth(authOptions);
export { handler as GET, handler as POST };

when hitting api/auth/signin it redirects to the LinkedIn login page, the login seems successful but then on redirect:

and in my console:

[next-auth][error][OAUTH_CALLBACK_ERROR] 
https://next-auth.js.org/errors#oauth_callback_error invalid_client (Client authentication failed) {
[...]
    name: 'OAuthCallbackError',
    code: undefined
  },
  providerId: 'linkedin',
  message: 'invalid_client (Client authentication failed)'
}

using:

    "next-auth": "^4.24.7",
    "openid-client": "^5.6.5",

What could be causing this? appreciate any and all help

[starbvuks]

So one error was a silly mistake on my part, the env var for the client secret is different than the var i mentioned in the route.js. Now im getting the error unexpected iss value, expected undefined, got: https://www.linkedin.com/oauth

other threads exist for this error: #8956