my iphone 12 keeps restarting by itself. i go the restore message and followed the directions up to the IOS reinstall but the restarting keeps happening

the iphone shuts off and the apple logo appears, this has happened multiple times over the past 3 days. The only thing that has been getting it to turn back on is plugging it in and waiting. Today the restore page came up, I followed the directions and reinstalled IOS and restarted the Iphone but the apple logo and black screen will not go away.