How can I set chat conversation header title as an end-user name without using pre-chat form dynamically?

• I want to set the end-user name as per my website logged-in user name.
• I have set the end user name through the

zE('webWidget', 'prefill', {
name: {
value: 'isamu',
readOnly: true // optional
}

});

• This code set the name only in the conversation but not set as a conversation header title. And this should be changed through the code or dynamically not manually.