Which episode revealed In-ho as a previous Squid game winner?

Was watching a couple Q&As on youtube with the actors and I learnt from Lee Byunghun himself that Front Man/In-ho was a previous squid game winner. I thought it was a spoiler and got sad a bit, but did some digging and found that everyone knows this too! Was this reveal one of the episodes of either season? Apparently I missed it completely... can someone help me out?