windows – ssh-add -s Win10

I am unable to add my card using ssh-add -s on Windows 10, ssh-agent is running. Getting below error: C:Program FilesYubicoYubico PIV Toolbin>ssh-add -s libykcs11.dll

Enter passphrase for PKCS#11:Could not add card “libykcs11.dll”: communication with agent failed

Can someone please let me know how keys(residing in PIV interface of yubikey) be added to ssh-agent for forwarding?

Thanks in advance