Unfortunately, this is still a missing feature in ShipStation. It is one of the most requested features in the ideas section of the ShipStation community, so we can hope it will be implemented one day. You can see the current status of this idea at the following link:
This idea was created more than five years ago, and it is currently in review. So, there is no telling how long it will be before this feature is added. If this is important to you, please upvote it on the ideas page I linked above. You can also comment on the idea to let ShipStation know it is far past time for them to add the ability this.