Elite: Dangerous PvE - Mobius

Guys, I realize this is (or should be) a stupid question, but I just can't figure this out. Passenger mission, passenger demands clothing. Fine, I go find and buy the 2 units of clothing. Then what? There seemed to be nothing for me to click or do to GIVE them the clothing, and it just sat in my cargo hold. Then when I give up trying to figure it out and assume "maybe it just has to be in the hold when you complete the mission", nope, it gave me the original reward price with no bonus and I still had these 2 damn units of clothing. How do I actually finish that part? I checked their email saying they wanted the clothing, and it had a check-mark button, but it was grayed out and I couldn't click it, even when I HAD the clothing...

Thanks a bunch.

Make sure to click the accept button on the INBOX message before buying the goods.

Thanks. That was it. I never clicked that. So after that, I just buy the stuff and it auto-completes?

It doesn't auto complete exactly but the mission will update once the items are onboard and the passenger will take the items with them when you drop them at their destination.