OpenID providers are not added if the contribution does not contain the ID and Secret

It works fine when I add the client ID and secret in the xml contribution. According to the documentation it should be possible to do it from the admin center in a second step but I could not make it work. The oauth2 provider is not created when the id and secret are not included in the xml contribution (actually none of the provider declared in the plugin are created: google, facebook, ...)