Firstly, we will see what is the use of document ID.
Document IDs help you manage your documents by providing an easy way to track items regardless of their location.
You must be a site collection administrator to activate the DOC ID Feature in a site collection.
Open SharePoint team site.
Navigate through site settings.
Under site collection administration, click site collection features.
Find Document ID Service then Click Activate.
Now the Document ID Service has been activated successfully.
Under site settings, click site collection administration.
Click Document ID Settings.
Check Assign Document ID’s.
Provide the “Begin IDs with the following characters”.
Click OK to complete.
Now Create a document library to check how it works.
Upload one document into this repository.
After complete document upload click on view properties of the document to see the Document ID has been included successfully.