try something

will doc later if works

app.py

@@ -65,10 +65,10 @@ def query_sql(user_query: str) -> str:
     # Log the generated SQL for debugging
     print(f"Generated SQL: {generated_sql}")
 
-#    if not generated_sql.strip().lower().startswith(("select", "show", "pragma")):
-#        return "Error: Only SELECT queries are allowed."
+    if not generated_sql.strip().lower().startswith(("select", "show", "pragma")):
+        return "Error: Only SELECT queries are allowed."
 
-    result = sql_engine(generated_sql)
+    result = string(sql_engine(generated_sql))
 
     print(f"SQL Query Result: {result}")