Good afternoon. In the box, all documents are linked to some object/entity (process, user, warehouse operation) and, accordingly, you can add it in editing the corresponding entity. First you must set up document templates
https://baltco.crm-onebox.com/admin/shop/document/templates/ . Then, for example, create a process and in the "Documents" tab generate a document on the process according to one of the created templates. Some of the templates you already have by default for example.