Push in airline leak

[4ways]

So my LT625 has an air leak from a brass push in quick connect airline (black 1/4” tube/hose) on the firewall near the steering linkage. From what Im seeing these quick connect fittings have an Oring that can be replaced. But I dont want to remove the fitting before I have the right Oring to put back in it. It’s in an awkward spot so I’m not going to try and change the Oring without removing the brass fitting.

Anyone ever change these orings and can point me toward buying them either from amazon or Napa or anywhere?

I would like to get a bunch in different sizes so I have them but at the moment Im mostly concerned about the one thats leaking.