Your LO should still have a copy, your lender certainly does, however, it may not be readily accessible especially if the loan or the servicing has been sold. I always send my clients a copy by email, you might try going back through your old email...or you may have saved a copy in your old documents list. The appraiser or their company may also be able to dig it up.
Remember though, a four year old appraisal might not be worth the effort to find it.
Best wishes, Jim