federal duck stamp and lifetime license

[cajun bill]

Haven't duck hunted in awhile, but will be doing so this weekend. Question: years ago, it was a reg that duck stamps (fed and state) had to be affixed to your license, but haven't duck hunted since I got a lifetime license a few years ago. I know the La. state duck stamp is part of the lifetime license, but the federal one is not so I bought one today. I know I have to sign it, but does the fed duck stamp have to be affixed to the lifetime license? I'm guessing yes, but after a few years, gonna get kinda thick on my license. Just wondering