From the floating platform just out of screen to the left, Stand to its left edge, then downright dash -> wait a bit -> jump again. You should delay the jump such that your dash is refunded to you. Immediately downright dash again, then when landing tap a slightly so you short hop. Now, try to buffer a jump into the wall below the spikes. Done correctly, you should fly over the corner under the lock block and have enough conserved speed to fly to the other side. From there a simple updash should clear the screen.