fix

app/main.py

@@ -39,7 +39,7 @@ def upload(files: list[UploadFile]):
     session_messages = []
     
     try:
-        os.mkdir("~/wtp_be_files/")
+        os.makedirs("~/wtp_be_files/")
         for file in files:
             try:
                 file.file.seek(0)