Sometimes book on NetGalley are not available for Request because the publisher is only allowing certain member types access at that moment, or the book is private and not available for request at all.
When there are no Request or Read Now buttons available for a book, members have the option to "wish" for it, indicating to the publisher that you are interested in accessing it. Publishers have the ability to "grant wishes" to randomly selected members, if they choose to do so.
If you are one of the lucky recipients of the book, you will receive a special email notifying you that your wish has been granted, and the book will appear on your NetGalley Dashboard like this:
You will also find the book on your Shelf under "Start Reading" - where you can click through to read more about the title and download it.
Please note that once your wish is granted, it will count as an approval, and will count towards your Feedback Ratio.
If your wish hasn't yet been granted, but the book becomes available to Request or Read Now, you will be notified in your Weekly NetGalley Checklist email. You will need to opt into receiving this email via your NetGalley Profile, and once opted-in, you will receive this email every Sunday. Read more here.