The currency collector is how you begin earning your currency, and one of two main ways to keep earning. You start the game by earning 1 currency per click, but this will go higher depending on your green upgrades.
Hint: Due to PC having more buttons to program into a game than a contoller or touchscreen; “more buttons” meaning an entire keyboard of letters, numbers, as well as a bunch of special keys, this allows the developers to have some fun with things.
Keep pressing on your spacebar as fast as you can. Each press of the spacebar will click the currency collector.
This works the same as speed tapping the button on mobile devices/touchscreen monitors, or your mouse button.
Alternate between left clicking and tapping the spacebar for the fastest results.