# description
POST /oauth/register — the registered client. Public client: there is no client_secret, and PKCE takes its place.

# properties.client_id.description
Pass this to /oauth/authorize and /oauth/token.

# properties.client_id_issued_at.description
Unix seconds when the client was registered.

# properties.redirect_uris.description
The registered redirect URIs. The one passed to /oauth/authorize must match an entry exactly.

# properties.token_endpoint_auth_method.description
Always `none` — the client is public and proves itself with PKCE.