From elevated command prompt,
Install license key - slmgr.vbs /ipk (License Key)
Activate license key - slmgr.vbs /ato (Activation Key)
Verify it is installed and activated: slmgr.vbs /dlv
ESU Program Activation IDs
Win10 ESU Year1f520e45e-7413-4a34-a497-d2765967d094
Win10 ESU Year21043add5-23b1-4afb-9a0f-64343c8f3f8d
Win10 ESU Year383d49986-add3-41d7-ba33-87c7bfb5c0fb