Need help, Power steering pressure line

The seal setup varies widely for the ps pressure hose to rack fitting on Mustangs.
The actual seal is the o ring that should go in a groove on the end of the tube, I think. ( I have not done one in a couple years)

My 79 vintage used a teflon o ring that has to be heated in warm water and carefully expanded to slip onto the tube. The threaded fitting does not seal any fluid, the tube end is captive inside the fitting (tube nut) and just holds the tube end and o ring into the fitting on the rack. similar at the ps pump.

If you look at it all, you should be able to figure it out. But you may need some more parts. Look closely at the old one....There are some different thread sizes, etc, etc.