How can you change the username of Fiverr? ?

Fiverr is an online freelancing plateforms working for many years and has quite good reputation in the freelancer market and people from all around the world visit and give orders to clients and they trust this plateform and order starts from 5$ to onwards. Everyone has a username to be identified uniquely either he is a client of a seller and no one can get that name. So you cannot change your fiverr username because it can get your old clients to find you hard and they will get confuse and this will lead to scams.