Function create_auth_endpoint 

pub fn create_auth_endpoint<F, Fut>(
    path: impl Into<String>,
    method: Method,
    options: AuthEndpointOptions,
    handler: F,
) -> AsyncAuthEndpoint
where
    F: Fn(AuthContext, ApiRequest) -> Fut + Send + Sync + Clone + 'static,
    Fut: Future<Output = Result<ApiResponse, RustAuthError>> + Send + 'static,

Defines an async auth endpoint without manual Box::pin.