Gerald, I'm not finding any cz 75 D compacts that are optics ready. So in order to add a red dot you would need a dovetail red dot adapter. It's a plate that replaces your rear sight to add a red dot that way. You could have a qualified gunsmith cut the slide for a red dot but that can get expensive. Sorry but hope this helps.

Gerald, the 75D is not optics ready. You would need to remove the rear sight and replace it with a dovetail mount.
amazon.com/DPP-Titanium-Dovetail-Compatible-Fastfire/dp/B09DP64JKG?th=1
Stay safe & have a great day!

Hi Gerald and welcome. If it does not have an Optics Cut Slide, you could use a dovetail (rear sight) optics mount. EGW can be contacted for fitment : mountsplus.com/egw-red-dot-mounts.html - Cheers and stay safe!