! Thanks for posting your question on the Essentials Trailblazer Community. Duplicate Management is available in Salesforce Essentials. You can find this feature in your Setup App under Data > Duplicate Management > Duplicate Rules. Here you can create rules specific for your Objects and business needs to create notifications and information about duplicates for your team.

Please also use this article from the Help & Training documentation to assist you in setting up these features. This article and it's sub-sections include walk-through videos to assist as well.