Hi,
You currently can’t do local notifications. Thunkable X supports OneSignal for push notifications. They do have an API also. You can send a push to specific devices so if you stored your device ID under the user ID in your Firebase then you could probably do something that way.
Someone else here in the community might drop in with an idea here on how to automate. I personally would just do this with a simple Python script. There may be straight forward services out there to accomplish this.
(edit)
This is what I’ve found using Zapier.
