Proactively engaging with the customer to renew or expand the contract is how the sales rep should adapt their sales activities to address the upcoming end-of-contract period for a key customer. Proactively engaging means reaching out to the customer before the contract expires, and initiating a conversation about their satisfaction, needs, and goals. This helps to build trust and loyalty, demonstrate value and differentiation, and identify opportunities to renew or upsell the contract. Reference: https://www.salesforce.com/resources/articles/account-management/#account-management-renewals