Notification from arduino to smartphone

Hi everyone,
I really need some help here as im super noob to arduino.
The problem: i have a small silo of a product and would like to connect an ultrasonic or LED/laser distance sensor to an arduino which is connected to ethernet and when the volume is low in the silo, i should get a notification on my phone that its low.

Can you guys help me with which components i need and maybe a general way to code it etc? Thanks in advance

Do you have some plan how to receive the notifications on the phone side? Some app you are going to build?

Have a look at this for inspiration:

You can try the Search Forum function, up to the right in this window.
Split the project into "Ardiono + distance".
Also go for "Arduino + ethernet".
When You master both You can make one code housing both.

Best to start learning Arduino here ... example sketches that are both in your IDE and online:
https://docs.arduino.cc/built-in-examples/

Your idea has probably been created. This will allow you to pick which project fits your idea.

As you will learn, the ultrasonic sensor and the LASER distance sensor are different devices that are operated differently.

What might that be?

vernacular: probably meaning silly, and probably better spelled, "sillo" to distance it from "dangerous thinking" (or a pit/tube for storage)

No, i do not, but this sound very good! Thanks a ton!

Not really relevant but i have a silo of wood firing pellets which i want to monitor its level.

In this case, with silo i mean a storage container for wheat for example.

Will do! Thanks for the tip!

Use wifi and an off-the-shelf wifi-camera to view the silage. Your livestock will thank you.

One of my friends is a professor of computer science (not the artistic branch of coding) who could easily build and code this. He opted for an off-the-shelf system, and can monitor his network of cameras from anywhere, at any time, including "in the dark" (with InfraRed).

A popular choice for similar applications is an ultrasonic sensor aimed down from the top.
The cheapest ones have a range of 4 m, but Maxbotics sells much better quality ones with longer ranges.

You can do that for free by having an ESP32 sending an email from yourself to yourself.
Leo..