Before exporting, it is worth checking that the model does not exceed the number of vertices specified (65,536 per segment). To do this, select:

View port > Statistics

Checking verticies amount in Blender

The next step is to convert all the curved planes to mesh. To do this, select:

select the curve > Object > Convert > Mesh

The next step is to perform an export to one of the data exchange formats, described in the next section.