Help Sekhema

Hello,
I just completed a Sekhema run with a friend, but I died on the final boss... literally at the last second. Unfortunately, he wasn't able to revive me.
It was my first personal trial (Trial 22), and I did complete the quest (yay!!), but now the game tells me I only need to turn it in. The problem is that I can't go back in because I no longer have a coin/relic (the round item you place on the altar at the beginning).
My question is: what can I do?
Thank you very much!