The most important thing is that the metal bracket, if that’s what you’re referring to, is not “lost” inside the iPhone housing where it might short other components when moving about. Turn off the iPhone and shake it..if you hear it moving loose, reopen the phone and put it back in place. If it jumped outside the phone, not a big deal, it’s better if it’s in place, but you’re not the first nor you’ll be the last using a 5S or a SE without it.