diff --git a/snippets/shx-3d-render-input.liquid b/snippets/shx-3d-render-input.liquid
index b990f3c..5332ffb 100644
--- a/snippets/shx-3d-render-input.liquid
+++ b/snippets/shx-3d-render-input.liquid
@@ -169,7 +169,7 @@
                 if(data.status === "init" ) {
                     const initData = JSON.stringify({"init":{"uuid":uuid}});
                     console.log("initData", initData    );
-                    Viewer3D.contentWindow.postMessage(initData, "*");
+                    this.Viewer3D.contentWindow.postMessage(initData, "*");
                     this.Viewer3DContainer.querySelector('.shx-loading-spinner-container').classList.remove('shx-loading-spinner-container-done');
                 }
                 return;