How can I set allowed notifications to vibrate only in Do Not Disturb mode?

I’m trying to setup my “do not disturb” (DND) focus mode to allow certain apps to send notifications, but to have those notifications vibrate only and not play the sounds I have set for them for when I’m not using a focus mode.

I’ve tried to do this by

selecting the apps to allow in DND mode.
And then setting up an automation to activate when DND is enabled that sets ringtone and media volumes to zero.

But I’m still getting notification sounds when DND is enabled.

I’ve tried to find any other sound option controls in Automations, but I’m not seeing anything that might control notifications or alerts.