Is DiscourseConnect enabled on your site? If not, you need to find the provider name of your authenticator and use that in the request. Some details about this are here: Find a user by their identity provider 'external ID'.
Is DiscourseConnect enabled on your site? If not, you need to find the provider name of your authenticator and use that in the request. Some details about this are here: Find a user by their identity provider 'external ID'.