Corebook p. 211

This basic mechanic of V5 activates most vampiric powers. It’s used to: Rouse the blood, activate most Discipline powers (if needed; it’s listed under the power’s activation cost), activating Blush of Life, waking up each night, mending damage. To perform each of these actions one must roll a Rouse Check.

Failing a Rouse Check doesn’t mean that the action cannot be performed: your intended effect is always successful. However, your Hunger will increase by 1. You only apply the Hunger increase after the roll for which you needed the Rouse Check, be it a Discipline or a Blood Surge. 

Rouse Checks
For Rouses that are awake up rouses there is a command built in called Rouse which you can use. If your character has two dice due things like Humanity 8 and Blush of Life, select the Reroll option before entering the Rouse command in #plz-roll-here