Well, then it may be a papillomavirus or wart. These can affect the beaks in some chickens, and many report that theirs eventually have fallen off. They are very similar to wart on people caused by human paillomavirus. Many animals have their own type. There is no treatment for most viruses, so probably not much you can do. The reason I asked about lesions elsewhere is that the picture resembles fowl pox scabs, another virus spread by mosquitoes. But it you are only seeing it on the beaks, it is more than likely papillomavirus. Here is more info about it:
https://vcahospitals.com/know-your-pet/papillomatosis-or-warts-in-birds
possible papillomavirus wart
