How do I collect two keys (F and J, for example) that are pressed simultaneously or very short apart

I am using Coder to make a visual feedback. Press F and J keys on the keyboard to give two graphics feedback on the left and right sides of the screen.

Now the problem is that these two feedbacks can only appear one by one. I hope the two feedbacks are independent, that is, even if two people press the same button, they can appear at the same time and be recorded separately and normally. Here‘s my code. THX :slight_smile: