How to set up a school bell?

Question

Helpdesk

Good afternoon, I ran into the task of setting up a school bell, but there is no marking on the bell itself, instructions and a person who would know how to set it up, also no, searching the Internet did not help. Perhaps someone has come across such a call (photo below) and knows how to set it up or has instructions.

There are three buttons on the right - blue, green, red.

Answer 1

Press the red button!

Answer 2

16:03 is the time. I need to find out how to put the school bell schedule in there.