This topic solves

The observer feature allows you to give other people access to documents to track them. You can also assign administrator rights to an observer to give that person the same permissions as an initiator, including the ability to add more observers or withdraw documents. Note that to add the observer, the expert settings must be enabled. If the document is already in the signature process, it is still possible to subsequently add another observer or remove an existing one. This video shows how to activate the expert settings, how to add an observer including administrator rights and how to subsequently mutate the observer.

Important: The observer function can only be used with the subscription Small.