To get a direct link to your book,
1. Go to https://okadabooks.com/store
2. Type in the title of your book in the search field, ensure you use any filter that applies by ticking the box (e.g. if you published it as an adult book, tick the adult book filter box)
3. Your book should show in the results. When it does, click it and when it opens, copy the unique link to the book and share.
Hope this helps.