If you are inquiring about the formats you can sell, please see: Selecting book formats to sell.
If you are uploading an ebook or have already uploaded an ebook, and need to link the ebook ISBN to a print ISBN so both books will be presented on the same book page, please read below.
Uploading an ebook:
During this upload process, you will be asked to input the print ISBN linked to the ebook ISBN.
Already uploaded the ebook:
Visit the book dashboard to input the print ISBN. Visuals are below: