​An apostille/certificate of authentication is a document intended for international use and is obtained only through the Kentucky  Secretary of State's Office. 

A certified copy of a vital record may be used for this purpose and may be obtained during the Secretary of State process. When requesting a certified copy of a vital record for an apostille/certificate of authentication, the Office of Vital Statistics must be informed that it will be used for this purpose. It is the responsibility of the customer to provide the certified copy to the Secretary of State's Office.

Contact the US State Department if you have any questions about  obtaining vital records from outside the US.

Getting Married in Kentucky: What Do You Need to Know?

Marriage licenses are issued in the county clerk's office in each county.  If you have any questions, please contact the county clerk's office in your area. Both bride and groom must appear together to get a license. Licenses are valid for 30 days from the date of issuance and the license fee is non-refundable. The license must be used within the state of Kentucky.