About fast sell option for Scalpers

Hii. This is Nitai. Another happy user of Dhan platform. In market I am a Scalper doing fast buy and sell in options. Dhan Provide a feature that call “Instant buy” in order panel. After clicking in "Instant buy feature I am able to buy within a second, but at the time of selling or exit the trade that option not available, so it takes few more second to execute not like the instant buy feature. Can anyone help me how to do fast exit in scalping. I request Dhan to make another feature like “Instant buy” for Exit the trade. Thank you.