Buying subscription during trial?

My friend recently joined Final Fantasy and has brought the standard edition of the game. We were seeking the friend recruitment rewards, however it seems like we cannot add game time without buying a time card. Is there anyway to get past this? Or we have to wait till the end of the thirty day trial (that comes with the standard game) expires?

If your friend purchased the game on stream he can purchase game time there. Otherwise, without buying game cards, you both will need to wait for his 30 day trial to expire so SE will bill him.

Aww. :( okay.