On the USB circuit board of the ESP32-CAM MB there are 2 very small parts to the left and right of the USB port, labeled with
"OI0" and "RST".
Are these jumpers or microswitches?
If there are jumpers: When (and how) do I have to pull them?

Yes - you are right! I have changed to a "form" and it works now. Learning by doing....

I'm working on a WEB server at a ESP32 to control a 3-color-LED. - The color picker ("colorpicker") from HTML5 is working - I can input a color with an input field named "selectedcolor" - But no GET request is done when the button (named "button") is pressed! - I do'nt use a form Can I get help to f...