Issue when using Query.equal in an appwrite function using python

Recently I faced an issue while executing the below function to generate a unique referralCode.

`from random import Random from appwrite.services.databases import Databases from appwrite.query import Query

def generateReferralCode(client)->str: databases = Databases(client) docs = { 'total': 1, } referralCode = None while (docs['total'] > 0): referralCode = Random().randint(100000, 999999) docs = databases.list_documents('USER_DATA', 'USERDATA', [ Query.equal('referralCode', referralCode) ]) return referralCode`

It shows me this error: Invalid query: {"method":"equal","attribute":"referralCode","values":["300522"]}

my collection has the following attributes:

name: String referralCode: Integer

This code used to work fine when I wrote it a few days ago, but now it throws an error.