To upload a book, you need to be in our "Bring Your Own Book" writing mode. You can switch to that mode in the "breadcrumb" menu by going here:

Author > Books > [Book Title] > Settings > Writing Mode

After you switch to "Bring Your Own Book" writing mode, you can then upload your book at a page that will appear here:

Author > Books > [Book Title] > Preview or Publish > Upload

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