Stupid question: How to trade with Cephalon Simaris?

[Say]

One of these quests i'm trying to do says I need to buy something from Cephalon. I met with him but the only options are "Do you have any targets?" "Would you like to run a simulation" "Would you like to do an onslaught"

[Donitsi]

When you walk in his room, behind Simaris on your right is his shop. It has glowing blue light which doesn't look obvious but just part of room decoration.