Generally you need to export a .stl file of the SketchUp model as that is the sort of file the slicer software is expecting. There’s no need to upload it to the Warehouse though. All recent versions of SketchUp can export .stl files natively. The key is to make sure you have created “solid” components or groups.
By the way, there are extensions like TIG’s Solid Solver and ThomThom’s Solid Inspector2 that are useful for 3D printing.