Permissions You must have Organization Administration Permissions.
In the Client Portal, there is no way to include a signature on EACH Intake Form. One signature is collected at the end just before they submit their Forms. Under the signature it clearly states that the signature will be applied to ALL information contained in the intake forms.
If you desire Client acknowledgement on each individual Form, you can edit each Form to include a mandatory Client acknowledgement such as Client Initials and Date using Short Answer field.