LinkedIn

LinkedIn has become an OpenID Connect compliant provider, avoiding the need for a custom OAuth2 implementation. Therefore, the linkedin_oauth2 provider is now deprecated. You can setup LinkedIn, like any other OpenID Connect provider, as follows:

SOCIALACCOUNT_PROVIDERS = {
    "openid_connect": {
        "APPS": [
            {
                "provider_id": "linkedin",
                "name": "LinkedIn",
                "client_id": "<insert-id>",
                "secret": "<insert-secret>",
                "settings": {
                    "server_url": "https://www.linkedin.com/oauth",
                },
            }
        ]
    }
}

App registration (get your key and secret here)

https://www.linkedin.com/secure/developer?newapp=