Challenge_text on passthru or passnotoken

Hello!
Is it possible to show a message when using the passthru or passnotoken policy? I tried using challenge_text but that didn’t work.
My goal is to show a message reminding users to activate the MFA feature during the system activation process.

Thanks

Imagine a user authenticating at a VPN.

Before the user enters his password, the privacyIDEA server can not know, that the user is about to authenticate.

When the user entered his password privacyIDEA sends a successful response to the VPN.

The VPN grants access and does not do challenge response. So there is technically no way to do this.

How do you think the user experience should look like?
Where should the messages be shown?
On an aircraft with tow advertising in the sky? sry :wink: