E-signature can be open by unauthorize user

I recently try Box Sign (E-signature) in my Company environment.

I found a possible security risk that E-signature can be open & sign by unauthorize user when I forward the notification email to other email.

This other email can open the sign link and signed as the intended person.

Could you add the option to make the user to login to the Box first before signing.

Thank you & best regards,

Ramdani