Usually, the notice of enlistment is an important personal file material. If you really can't get it back, you can try to reissue it through the local recruitment office. It should be noted that the number on the enlistment notice is unique, so the reissued certificate may have a new number. During this period, you can ask the relevant departments to provide certificates or related materials to prove your enlistment status. If necessary, you can also consult legal professionals or relevant institutions to ensure that all necessary procedures and documents are properly handled.