To export an FDM 3D model, save your design from 3D modeling software (e.g., Blender, Fusion 360) as an STL or OBJ file—these formats are FDM-compatible—and convert it to G-code using a slicer tool.
STL/OBJ files store only the model’s shape (no color/texture), which slicers like Cura or PrusaSlicer need to generate G-code (the printer’s instructions). Import the file into your slicer, tweak settings (layer height, infill), then export the G-code to a USB/SD card for printing.
For beginners, stick with STL—it’s widely supported. Just ensure your model is watertight (no gaps/holes) to avoid slicing errors.