I think what you are looking for is the Emboss tool on the 3d modeling ribbon.
the following is the help section on the command. To clarify the help section a little create a solid first, then create a sketch on the solid of the shape you want to emboss and then use the tool.
http://help.autodesk.com/view/INVNTOR/2020/ENU/?guid=GUID-E6848555-B274-4858-8401-84E260771E84