Edit to add: remember to staple so the two pointy bits of the staple are on the outside of the mask. Otherwise you're going to have them scratching your chin area. I've done this type of stapling on the Dräger X-plore 1920 but stopped buying those because I had other stuff that fit me better and wasn't quite as expensive.
screengrab of a tweet by @yesallcrops from Feb 13, 2023. They wrote "I've mentioned that I have to staple all my masks tighter to fit my face shape. If I don't do this, I can feel air rushing out through the chin portion. Here's how I do that! (Try pinching the extra fabric under your chin while the mask is on to know where to staple)" There is a video of a person dressed in a black top with a V-neck. The hold a respirator in their hands. Then they pinch a bit of material in the middle of the chin area and use a small stapler to staple that pleat into place.