I've missed 2 months of payments on the standard plan and one on the premium plan. How do I pay them now?

I'll answer for this. It is designed to be monthly but since there isn't a notification tool build we aren't enforcing that st this time and it is kind of an honor system. So no worries if it shows you have an unpaid balance/invoice. No one is getting booted from the relay for that until we communicate a standard around that (which will likely be posted on the #PodSystems website). And for clarity, all relay subscribion payments, including the NIP5 IDs, go directly relay overhead. Zaps to both nostr:npub1h8lhed2da096g2wcsh2crmyvenune046rqkejc8f8pcaag8qj25qqadp5p & nostr:npub1updmknky86nsph84rstlh0yymqpeg9l9f62qgxwvd6a75f3pvzxqxv83nv are the same lightning address and used for joint projects.
I've missed 2 months of payments on the standard plan and one on the premium plan. How do I pay them now?

You should be able to pay them individually or as one bulk payment. The custom amount option will let you imput whatever ammount you like.