Then bind the keys in ~/.config/hypr/bindings.lua. Super+D is free in Omarchy; Alt+Tab replaces “focus next window”:
o.bind("SUPER + D", "Exposé", "omarchy-shell -q quebecstudio.qexpose toggle")
o.rebind("ALT + TAB", "Window switcher (next)", "omarchy-shell -q quebecstudio.qexpose switcherNext")