In Japan there are intersections, usually attached to main thoroughfares, where the light will stay green for the busy road until a car approaches from the smaller road or the crosswalk button is pressed.

These days, most crosswalks are on a timer. But, if you see a button, you usually have to press it. A light above the button indicates it has been pressed and will either cycle the lights immediately or wait until the next timed cycle.

(Some older crosswalks that have since been automated still have buttons attached to the light poles, pressing those buttons do nothing because they’ve already been activated by the computer controlling the light timer. The activation light above the button is always lit.)

(Sorry, this was meant as a response to @NaibofTabr@infosec.pub.)