why is it a draw?

take a look at my game

Your time had run out and since White has not material to mate you, it's a draw.

It's a draw because even if you had time on the clock he would never be able to checkmate you due to only having a king and no other pieces. If he had at least another piece (even a pawn) it would have been a win for him, because then a checkmate would be possible.

how about a knight or bishop @Dario19503

@NaTbEe Any other piece that your opponent could've had would've resulted in your loss, there is a possible mating picture.
If he had a knight: Position: Black: Ka1, Nb1 White: Kb3, Nd4; White to move plays Nc2#
If he had a bishop: Position: Black: Ka1, Nb1 White: Kb3, Bc1; White to move plays Bb2#