Update app.py

app.py

@@ -10,7 +10,7 @@ def process_survey(survey_id, submission_id):
 
     encoded_params = urlencode(params) 
 
-    match_param = f'{"_id": {"$oid": "{submission_id}"}}'
+    match_param = f'{{"_id": {{"$oid": "{submission_id}"}}}}'
     encoded_match_param = quote(match_param)
 
     survey_url = f"{base_url}?{encoded_params}&match={encoded_match_param}"