De-duplicate option in a Custom Module

De-duplicate option in a Custom Module

I wish to have the de-duplicate option in a custom module. Though de-duplicate can be seen in other modules like Leads and Contacts, the option does not exist for Custom Modules.

Moderation Update:
The Find and Merge duplicates, and Deduplication feature is now opened for the users. 
Announcement post: 
​https://help.zoho.com/portal/en/community/topic/improvements-to-finding-and-merging-duplicate-records-in-crm