No "done" button when trying to write a book

So frustrated. When writing a book, there is no 'Done' Button. Its either sign it, or nothing. Which means then the book can no longer be edited. I need a book that I can use to send messages to others on the server as the signs in bedrock also have the issue of disappearing as soon as you write them. I cannot communicate AT ALL on a server that I play with friends and have to be on a phone call to communicate.