How do i export stl file?

[cmw1017]

I want export STL file from Scene3D class.

It is error log in chrome.
STLExporter.js:25 Uncaught TypeError: Cannot read properties of undefined (reading 'traverse') at STLExporter.parse (STLExporter.js:25) at HTMLButtonElement.<anonymous> (test10:73)

It is my export code...
document.getElementById( 'export' ).addEventListener('click', function() { var exporter = new STLExporter(); var blob = new Blob( [ exporter.parse( this.scene ) ] ); var a = document.body.appendChild( document.createElement( 'a' ) ); a.href = window.URL.createObjectURL( blob ); a.download = 'file.stl'; a.click(); })

what is my problem.. can you help me..