No your fingernails are not digestible so it's not a good thing to eat your fingernails.
Although if you do eat your fingernails either intentionally or accidentally the fingernails would just come out eventually in your poop.
But eating or biting fingernails could cause worms and other parasites to enter your body due to bad bacteria that can be hiding underneath your fingernails or on the fingernails.
There was a guy I read about online before that almost died as a result of eating his fingernails so you should not try to eat your fingernails as it's never healthy and can make you sick.
Most people have chewed on and eaten their fingernails without any health issues but it's not worth the risk.