How to display an event driven diagram in UML?

Question

UML

Friends, good time!
Can you please tell me how to display on the diagram the behavior (of the flowchart type) of the program depending on the events?
For example, the blocks are standard: initialization of all data, rendering of controls, waiting for user interactions.... and then you need to display the behavior of the program in blocks on different events (closing the program, pressing such and such a button, etc.).
Thanks to!:)