How do I add subscription time?

[wassup]

Greetings Enkidoh and thank you for responding. I have logged back in to the Mog Station just now and I swear that Manage Service Options button was not there earlier, yet it is now, so I've clicked that and see the following options:

Enter the Registration code for the Expansion / Digital Upgrade
Steam Payment (i dont utilize a steam wallet to my knowledge, I'm noob with Steam..) / Retainer Service / Enter Item Code / Recruit a Friend / Add ps3 License / Add ps4 License / Add Mac License

then it just shows Account Type (windows a realm reborn) and a Cancel Service Account button (also a view veteran rewards hotlink)

maybe I'm not seeing it because it's still on the 30 day trial? (I find every part of this stuff utterly confusing)


EDIT: OOOOOOOOOOH i think i found it