Did you ask the plan for another copy? Or you can probably log on to your retirement website and download it or print it. The companies are starting to only provide them online that you have to get your self.
Did you have one last year? You might be able to import it to Turbo Tax if you have the some info from it . How to import a 1099
https://ttlc.intuit.com/community/entering-importing/help/how-do-i-import-my-1099/01/26254
