The fitting provided should look like the OEM one below. If you look closely, it has two O-rings; the white one about mid way that seals the fitting against the pump body, and a black O-ring in the bore of the fitting (you can just see it at the top) that seals the ps line against the fitting bore.
iirc, the ps line has a narrow groove machined in it and the fitting has a tiny circlip below the black O-ring in the bore (not visible) that clicks into the groove of the ps line to hold the fitting positively on the end of the line.
When I came time to relocate my ps line, I replaced a section of the pump end of the line with a new ps line and fitting and used a compression fitting to join the new and old line (so I didn't have to mess with the rack end.)
You're dealing with very high working pressure in the ps line so the leak proof sealing of the components isn't always as simple as it seems.
Not sure if that helps any.