The crust mixture is quite crumbly before pressing it into the pan. Just press it down and it’ll make a fine crust. If it sticks to your fingers, try using the back of a soup spoon or lay a piece of parchment paper over the crust while pressing it in. Also don’t forget to build up the edges of the crust about 1/2 inch (1 cm).
Lemon Bars https://livingoncookies.com/lemon-bars/