Palette 2 is currently not able to connect directly with a Duet 3d WiFi board. We have not yet assessed the feasibility of providing a plug-in here; OctoPrint was most requested so our efforts have been focused here for now.
If Duet can accept g-code serially over USB, CANVAS Hub would be able to provide a link between the printer and Palette 2. This workflow would however not use the Duet WiFi interface/functionality. We recently had a Facebook user find success connecting a Raspberry Pi with OctoPrint to their Artemis printer that uses a DuetWifi board.
If you have any additional questions, please send us a message at firstname.lastname@example.org.