YunoHost's permissions system allows you to select which users can have access to Node-RED:

* `main` permission protects `/admin`, the flows editor. The administrator is chosen during installation ;
* `ui` permission protects `/ui`, the dashboard allowing visual interface for the flows. Public access is chosen during installation ;
* `endpoints` permission protects `/`, for API-like endpoints. Public access is chosen during installation.

If you have upgraded Node-RED beyond v2, check that these permissions suit you in your YunoHost admin panel.