How can I pull images from mycloud.com and show them in my website? I have not created any account (developer account etc) in mycloud.com but eager to know whether any API in PHP scripting language is available or not?
Officially you cannot. This has been discussed previously:
https://community.wd.com/t/can-only-download-pictures-via-link-not-view-in-browser/170509
https://community.wd.com/t/using-my-mycloud-to-host-my-blog-photos/155738
https://community.wd.com/t/direct-link/145919
Unofficially it may be possible using a third party OS (depending on single bay My Cloud version) or SSH/FTP.
https://community.wd.com/t/clean-os-debian-openmediavault-and-other-firmwares/93714