Looking for logging into the Ibooks Sign In site and are not getting the correct working link for it? In such a case, you can use the links given here by searching your desired login page in the search box. If the page is present on our website then you will get all the links related to the Ibooks Sign In site. After that you can login as usual with your login credentials.
https://support.apple.com/en-ae/HT201762
https://www.apple.com/ae/apple-books/
https://support.apple.com/ibooks
https://support.apple.com/en-ae/HT201183
https://itunesconnect.apple.com/
https://support.apple.com/en-ae/HT201400
https://discussions.apple.com/thread/4475702
https://www.tenorshare.com/fix-iphone/fix-ibooks-not-working-on-iphone.html
https://apple.stackexchange.com/questions/298552/unable-to-login-with-apple-id-in-ibooks-author
https://www.igeeksblog.com/how-to-sync-ibooks-to-all-your-ios-devices/
https://docs.jamf.com/10.0.0/jamf-pro/administrator-guide/eBooks_Available_in_the_iBooks_Store.html
http://www.startribune.com/how-to-read-itunes-books-on-your-pc/160428925/
https://www.idownloadblog.com/2015/12/07/how-to-disable-password-prompts-ibooks-store-mac/