Export the flat face of the part at 1:1 scaling, with no borders, dimensions, or other information.
Project the body’s edges to the plane parallel with the X/Y plane. After that, the drawing will be able to export correctly in a DXF. You can see more advice from a Shapr forum here.
Please note, Shapr3D is not one of our recommended software. We have information about design programs we support here: Recommended Software for Laser Cutting
After exporting, you can upload your file to our website and check the part preview to verify that the overall dimensions are correct. All files need to be at 1:1 scaling in either millimeters or inch units, with no intersecting or duplicate paths. We have more information about our design requirements here: SendCutSend Design Guidelines
For general preflight, the free, open source program QCAD is great for checking 2D files. If you end up liking it, we have guidance on reviewing designs in QCAD here: How To Preflight Your Designs Using QCAD
