Sorry for the delay in response.
This service wasn't integrated with Acrobat 9. It is with Acrobat XI or later versions.
"Send for Signature" option is available with Acrobat or Reader DC: Send PDF documents for signature, Adobe Acrobat
Reader users will only have access to " Send for Signature" if they have purchased Adobe "PDF Pack" or "Send or Send for Signature" service. For Acrobat users this will be available to CreativeCloud or DocumentCloud subscribes users only not classic(or Perpetual) users.
Hope that answers your question.