Quick question how custom packs work

Currently trying to do a custom progression series with a friend of mine and I'm making the packs. I'm trying to use the CSV import feature for the custom pack creation because that's a fair bit faster than adding each card individually but I cannot make it work. 

I first make the packs in ygo pro and save them as a deck (one copy of each card I want in the pack across two decks, for a total of 100). I then open the deck in excel which gives me the card IDs, and I then assign a rarity to each card as the custom pack creation page suggests after which I save it as a CSV file but trying to import it into the custom pack creator does absolutely nothing.

Anyone has any experience with this or even a faster way alternative way of making custom packs for a progression series?

Thanks in advance.

Hello!

Can you shoot me the CSV you are trying to import to [email protected] and I'll investigate!

ygoprodeck:

Hello!

Can you shoot me the CSV you are trying to import to [email protected] and I'll investigate!

Thank you for the quick response! 

It's fine now, it was my mistake. I had assumed that IDs worked with the custom pack creator but it explicitly needed card names. I just uploaded the decks for the pack into collection here and then downloaded my collection as CSV and edited the rarities and it works like a charm.

Thanks again!