fix: import settings object of Settings class in mongo_db.py

application/core/mongo_db.py

@@ -1,4 +1,4 @@
-from application.core.settings import Settings
+from application.core.settings import settings
 from pymongo import MongoClient
 
 
@@ -11,7 +11,7 @@ class MongoDB:
         Get the MongoDB client instance, creating it if necessary.
         """
         if cls._client is None:
-            cls._client = MongoClient(Settings.MONGO_URI)
+            cls._client = MongoClient(settings.MONGO_URI)
         return cls._client
 
     @classmethod