You can create a center-line on architectural drawing given by the architect in AutoCAD or similar software and save those in DXF format.
Click on Upload DXF. This command is used to upload a DXF format file to the user/guest directory
File upload panel becomes visible.
Click on Browse...
Select a DXF format File Name on your computer. It should not have its name same as any existing project.
The DXF file name must be alphanumeric.
Click Upload.
The application will create a new project of uploaded file name. Use Open Project to open the new project.