Try that,
And this:
https://www.amazon.com/gp/aw/s/ref=is_s_ss_i_0_6?k=galco+shoulder+holster&sprefix=galco+
It all depends on what gun you have though.
IWB holsters-
I have no experience with a real quality shoulder holster, as I am not a fan of them for serious work. The above belts, and holsters are a sample of great choices I personally own/use everyday on or off duty. Good luck