Some pockets I can't really draw from so I just purchased from Bare Arms Holsters. Just put a note that it's for the Gen 4.https://barearmsholsters.com/
Check out Detriot Kydex (www.icarryguns.com). They make IWB holsters for Diamondback handguns. They also sell on eBay (https://www.ebay.com/str/detroitkydexholsters).
I'm a big fan of Boraii, been using their DB9 pocket holster for about 3 years because it fits in the back pocket of my jeans, now thinking of ordering an IWB from them, anybody got any experience with their IWB holsters, the one with the claw to keep it tighter to the body looks interesting but I think the DB9 is small enough the minimalist design is enough, and cheaper. Here's a link to compare the three they make for DB9 and fit all Gens, https://www.boraii.com/store/checkout#cartLifetime warranty too, given that even Kydex cracks after awhile...