Use 'requisite' to stress the importance of something being particularly necessary in that context. A passport is the requisite document for international travel.
Pro Tip 2/3
Implicit Urgency
'Requisite' often implies an urgent or immediate need within a specific situation. Your immediate attention is the requisite action to address this issue.
Pro Tip 3/3
Professional Tone
The term 'requisite' is typically used in formal or professional contexts. The job offer was contingent upon the requisite background check.