Last week I released the iOS app Pushcut which integrates push notifications with customizable actions that can either be iOS shortcuts or URLs. You can trigger the notification through a HTTP web API. I am sure it can be combined with NodeRED in wonderful ways.
For pro users, it also supports a powerful JSON API to fully customize your notifications dynamically.
I was mainly driven by my desire to have a good way to communicate with my openHAB home automation in smart way - I wanted the right options at the right time. I use HomeKit and web requests in shortcuts to communicate back from my notifications.