gistfile1.js

function exportZipToSketchfab( zip ) {

	setLoadingText( 'Uploading...' );
	showLoading( true );

	var fd = new FormData();

	fd.append('token', settings.sketchfabToken );
	
	fd.append('fileModel', zip );
	fd.append('filenameModel', 'model.zip');

	function updateProgress( e ) {

		if (e.lengthComputable) {
			setProgress( e.loaded / e.total );
		} else {
			setProgress( 0 );
		}

	}

	var result = function () {
		var res = JSON.parse(xhr.responseText);
		console.log(res);
		if (!res.success) {
			showMessage( 'Sketchfab upload error: <span class="error">' + res.error + '</span>' );
			showLoading( false );
		} else {
			showMessage( 'Upload success: ID is ' + res.result.id );
			showLoading( false );
		}
	};
	
	var xhr = new XMLHttpRequest();
	xhr.upload.addEventListener( 'progress', updateProgress, false);
	xhr.addEventListener( 'progress', updateProgress, false);
	xhr.addEventListener('load', result, true);

	xhr.open('POST', 'https://api.sketchfab.com/v1/models');
	xhr.send(fd);

};