Here my code

  new_key= ndb.Key(urlsafe = request.user_key)

this is written in python3 ndb
this will return us key and we change in urlsafe

key = new_key.urlsafe()
key.decode(encoding="utf-8")

but this is not return us new key which does not match with python2 key

now google app engine has change not sport python2 but they gave us this method

to_old_key

but this does not work

https://googleapis.dev/python/python-ndb/latest/key.html
https://googleapis.dev/python/python-ndb/latest/_modules/google/cloud/ndb/key.html#Key.to_old_key

how can we use this