How to remove an image copy when optimizing - plugin Litespeed cache

I used the image optimization feature in Litespeed cache and did not open the original image deletion after optimization. So my vps drive has doubled. Now what should I do to delete the original images to keep the optimized images. I turned on the delete function right below the optimization button and backed up the original image with the folder, but it did not decrease. Please help me with a solution. Thank you !

img: Imgur: The magic of the Internet