Accursed Pact - where is the "item chest"? Help.

The text about accursed pacts tells "accept any of three random Accursed Pacts which grants both an upside and downside, as well as an item chest upon accepting at least 1 Accursed Pact".

Completed sanctum run but got no chests in the end.

Where is it? Maybe I missed it.

Or maybe my level is too low?

Help!

The "item chest" is the offer right behind the accursed pact. You can't interact with it until you accept at least 1 pact. Once you do, you can pay 5 coins to accept a prize.