Update app.py

app.py

@@ -2300,9 +2300,9 @@ def download_sb3(project_id):
 
 @app.route("/download_pdf/<project_id>", methods=["GET"])
 def download_pdf(project_id):
-    pdf_path = GEN_PROJECT_DIR / f"{project_id}.pdf"
-    # if not pdf_path.exists():
-    #     return jsonify({"error": "Scratch project file not found"}), 404
+    pdf_path = GEN_PROJECT_DIR / project_id / f"{project_id}.pdf"
+    if not pdf_path.exists():
+        return jsonify({"error": "Scratch project file not found"}), 404
 
     return send_file(
         pdf_path,