Friend bought PSN download, but doesn't know where to get promotion code it asks for.

A friend of mine decided to try the game and bought the download version from PSN. When he tried to get on the game it asked for a 12 digit promotion code. He has no idea where to find this code at. Back at launch I bought the hard copy (disc) which included the code in it, so I have no idea where those that download the game get it. He went and registered for SE account. He actually gave up searching after spending an entire evening looking and doing online research about it, so I told him I'd help.

Can anyone that has bought the game via PSN download help? Or anyone that knows? Game won't let him on without that code.

EDIT: Just to be clear I already told him to check PSN email day before posting this, but he never replied to me on that, and instead kept saying he was researching where to find code. So I assume he didn't get email. I asked him again if he checked it, and waiting until he gets on for reply.

For my PC version, it was printed in my purchase receipt and they sent me a separate email as well (Gamestop). It's also available when I log back into my account and go to my downloads section.

It might be that way on the PSN store as well. When I had to keep re-downloading Left Behind until it installed cleanly, the code was there every time I went to kick off the process again.

Guess I could tell him to check his downloads section.