Yes, in most cases ShipStation can automatically sign your customs forms!*
Click Settings (the Wrench icon in the upper right).
Next, select Shipping and then International Settings from the sidebar on the left.
Here you can set defaults for customs information, and fill in the Sign Customs As field.
Generally, you want this to be your actual name versus your company's name.
*Please note that FedEx does not support populating the Signature field on their Commercial Invoices. However, ShipStation supports the Electronic Submission of customs information through FedEx, so printing, signing and attaching these forms to FedEx packages should not be required. For more information on that process, refer to our help article about electronically submitting customs forms.