Hero Coins from last month's Pass Royale?

I was not collecting the Hero Coins from last month's Pass Royale on my second account, as I had no card leveled up that could be a hero. I already had 275 Coins and did not want them to convert into gems.

I wanted to collect them now, as I had a 5 star chest giving me lots of goblins which I then unlocked as a hero.

I don't see any possibility in the Pass Royale to collect anything from last month. Did they remove this or is it not possible specifically for Hero Coins?