I use FreeCAD to import an SVG and export it as a DXF that can be imported into Shapr.
I use illustrator…
Inkscape is free it’s even on linux but desktop only, if you are on iPad Affinity Designer is a good paid option to convert SVG to DXF.
Until Shapr implements SVG these are the workarounds, but if you deal with SVG it’s just good to have at least a vector program to do some cleanups.