As an admin of your company, you can push styles (or stijlen in dutch) in the top menu bar. If you then choose a style and press on edit. You will land on the edit page of this specific style. Next press advanced. Here you will see some features that can influence the look of your export. One of these features is adding a header or footer logo.
There are also a lot of other nice features. Tried to play around with them and make something beautiful. PS: You can make a separate style for you documents if you’d like to.