error Too many parameters for command open

This is my script


option batch on
option confirm off
open sftp://ASIAPACIFIC\$gemsftp001@gvw1626.austin.hp.com -privatekey=C:\Program Files (x86)\WinSCP\private-key.ppk


when i am running this script i am getting this error

Too many parameters for command open

pleas help me in this

Have you read this FAQ?
https://winscp.net/eng/docs/faq_script_switch