How to earn certain amount of money in under X amount of seconds, With high score

I want to add this little side mini game to my Clicker, where you have to earn X amount of money in X amount of seconds, and it shows your high score and saves it until you beat it, can someone help me with this?

 

What have you tried?

 

I think this could be realized with a queue. You can enqueue any earning and then check if the oldest elements in the queue are still inside the given time frame. If they are older than X seconds, they have to be dequeued. When you dequeued all old earnings, you can iterate over the queue and sum up all earnings.

 

I havent tried anything yet, because I have no clue how to even go about it

 

At this point, I may only suggest to start from basics.
See Learn section.
Because I wont know, what you know already and what don't.