Passive perception

I'm trying to make a Passive Perception token, so that when PCs land on a specific square the chat will show the message ONLY to the DM. I'm using a Token with a Reaction to Send To Chat with: /w dm check perception 15 /gmroll d20  I think the problem is that since the player is triggering it, it includes the message to the player. Is there a way to have the chat only go to the DM? Or is there another way to do this?

Instead of  /ssr for the super secret roll. It is specifically designed for reactions.  Example:  /ssr 1d20 Perception check vs DC 15 Secret Roll: /sr Super Secret Roll (for use with Reactions): /ssr Secret Whisper to the GM: /s Both Secret Roll and Secret Whisper will tell the player they are sending a secret roll/whisper to the GM.  Super Secret Roll does not tell the player anything, they never know about it. 

Awesome! This is exactly what I was looking for.