There's no such thing as a draw by perpetual check.
One of two things are gonna happen:
- The same position is going to be repeated 3 times
- There will be 50 moves without a capture or a pawn move
As soon as either of these are true, you have to click the Draw button, and the draw will be awarded.
Will game automatically draw during perpetual check? I have checked my opponent 20 times but he will not accept a draw. He can move his king to different squares each time but can't stop check.