You may not have an online access code, not everybody does. It will depend on how you applied.
But when did he enter the US on his immigrant visa, and when did you pay the green card fee?
Edit: looks like he's only just entered? Have another read of your previous thread, he isn't due to get his green card until up to 90 AFTER he's entered the US on his visa, so still another couple of months for it to potentially be received.
You can check the status online (your online account won't help with that anyway). You need to do the case status checker and that will tell you when the card is in production, when it's been produced, when it's been shipped etc - https://egov.uscis.gov