It depends on the typing speed. If you type fast enough, the request won’t be sent for each keystroke. The widget debounces sending the request every 400 milliseconds, if user types below that threshold, the request won’t be sent. Tested on Safari/Firefox/Chrome on macOS, it works well on each.
You can see this as proof:
It only sent two requests between typing “Theme component data” and “Theme component data expl”, i.e. no requests for the characters in between.