You can simply go to their site and verify the authenticity as well as match up the picture of the item. I have printed out a copy of the page and will include that with the baseball.
Professional Sports Authenticator (PSA) is the largest and most trusted third-party grading and authentication company in the world. Cards and collectibles graded by PSA are worth considerably more than those that are not and for good reason. Founded in 1991, PSA has processed over 20 million cards and collectibles with a cumulative declared value of over a billion dollars.
Each month we process approximately 100,000 submissions from hobbyists who are serious about maximizing the value of their collections. By providing the advantage and protection of impartial, third-party grading, PSA has created a market in which collectors can participate with complete confidence and trust. Please check out our other auctions for some more great hand signed memorabilia with 3rd party authentication! The item "CHICAGO CUBS JOHN LACKEY signed 2016 WORLD SERIES OFFICIAL BASEBALL OML PSA JSA" is in sale since Sunday, May 3, 2020.This item is in the category "Sports Mem, Cards & Fan Shop\Autographs-Original\Baseball-MLB\Balls". The seller is "blamejameis" and is located in Clearwater, Florida. This item can be shipped worldwide.