Every author in Scopus is assigned an Author-ID. In order to retrieve accurate H-Index score, its important that all your publications are correctly associated with your ID. Scopus assigns a number for you automatically, but you may have more than one profile in the system. Or, you may find that your publications are assigned to a different author ID. To make corrections to your profile, use the Author Feedback Wizard:
Once you all your publications are associated with a single author profile in Scopus, you can send this list to ORCID.
"The easiest way to manage your profile is through the Scopus to ORCID wizard: http://orcid.scopusfeedback.com/. Follow the steps in this wizard to create a single profile containing all of your publications and to ensure your corrections are sent to Scopus. If you choose to create an ORCID ID (or link your existing ORCID ID with your Scopus author identifier), you’ll see a link to that ORCID ID on your Scopus author details page."
Not sure why you need an ORCID iD? This video tells you what ORCID is all about.