"New Project" is nearly identical with the Wizard "Create project" in WebOffice author standalone. To create a new project you have to enter the project name, the map, geometry and output service as well as an overview map and a basemap.
Step 1: Project ID
Go to File -> New Project. Enter the Project ID and the Project name. The WebOffice 10.6 project will be started in browser using the project ID as an URL parameter (e.g. project=Testproject). Be sure not to use any special character, german umlauts or spaces in the project ID. The project name will be displayed in the title bar of the WebOffice author and the browser. Optionally configure a user and a password to activate User Management light.

Wizard "New Project" - project settings
Click Next.
Step 2: Main Map Service
Choose an already existing ArcGIS Server 10.5.1 account (or create a new one). Enter the REST-URL of the map service you want to use as a main map service. You will find this on your ArcGIS Server Manager -> Services. Choose your Service and click on functions.

Wizard "New Project" - Main Map Service
Click Next.
Step 3: Geometry Service
Now it is necessary to add a geometry service to the WebOffice 10.6 project configuration.
The geometry service is create automatically with the installation of ArcGIS Server 10.5.1 in the folder Utilities. Initially, this service is stopped. You can start it directly via ArcGIS Server. The default path is already used as the Service URL in this step.

Wizard "New Project" - Geometry Service
Click Next.
Step 4: Output Service
The URL to the Output Service can also be found using your ArcGIS Server Manager. The default path of the Output Service is also already used in the project wizard.
Note: Don't forget to check, if your Output Service has been started. More information on Publishing the SynOutputService.

Wizard "New Project" - Output Service
Click Next.
Step 5: Overview service type
WebOffice 10.6 projects can be configured with overview maps. Please select an overview service type in this step:
•No Overview map
•ArcGIS Server Map Service
•ArcGIS Online (preconfigured)
•OpenStreetMap

Wizard "New Project" - Overview map
Click Next.
Note: If you have chosen "No overview map" or "OpenStreetMap" there will be no fields to configure. When choosing ArcGIS Server map service please select the ArcGIS Server Publisher Account and the Service URL. When choosing ArcGIS Online you have the choice between four layers World Topographic Map, World Street Map, World Light Gray Basemap and World Dark Gray Basemap.
Step 6: Basemaps
Decide whether you want to add an external basemap or not. You have the choice between several Basemaps from ArcGIS Online, OpenStreetMap or Bing Maps. Please be aware that you need a token, when choosing Bing Maps. You can also select an empty Basemap. Please also choose your default Map View.
Note: WebOffice author needs a working internet connection to access external services.

Wizard "New Project" - Basemaps
Click Next.
Step 7: Finish
WebOffice author standalone shows a summary of the project that will be created.
Click Finish in order to save the project configuration.

Wizard "New Project" - Finish