There are some IWB holsters that claim you can tuck in your shirt and that the gun will not be noticeable. I have never actually seen one that works, but truthfully haven’t searched too much. I suppose you could explore the possibility of an ankle holster or maybe one of those
holster type t-shirts.
Probably the best option is a pocket gun like the LCP or a J-Frame. I have carried both very easily while dressed in khakis or tailored dress pants.