Documentation for redirect_uri with volto

I am configuring volto for openid and the documentation confused me. It says

```
redirect_uris: this needs to match the public URL where the user will be redirected after the login flow is completed. It needs to include the /Plone/acl_users/oidc/callback part. When using Volto you need to expose Plone somehow to have the login process finish correctly.
```

So I wondered but did so ... and after login I was in classicui (what I did not want).

The documentation also says:

```
Also, on the OpenID provider, configure the Redirect URL as /login-oidc/oidc.
```

So I tried /login-oidc/oidc as redirect_uri in @@oidc-controlpanel. And this works without exposing Plone Backend and after login I am still in volto.

Is this the correct way to configure the oidc plugin for volto? Did I miss some documentation?