I found the solution to one of my problems. See https://forum.lvgl.io/t/using-the-button-input-device/2077/3. The documentation was rather unclear on what the various bits do…
Now, still, how to a simulate a click on one or more points on the screen. My aim is to be able to simultaneously press two logical buttons thus emulating somoething of the play/record buttons of an old cassette tape recorder.