Post TeamMessaging on behalf of others (Impersonate messages)

Make the body of your post like this

var body = {
    icon: "http://www.somedomain.com/icons/avatar.png", // publicly accessible
    activity: "Display name ABC",
    title: "Some title",
    body: "Your message"
  }

Thanks @Phong Vu ,
We can able to change the displayName but icon is still showing from incoming webhook.
We created the incoming webhook using REST API with Bot Token.

Payload for the incoming webhook :

{

"icon":"https://i.stack.imgur.com/l60Hf.png",

"activity": "Jack",

"body": "Your message",

"text": "Welcome"

}

Note: It is not working for posting message through REST API.

Is there anything we need to add to change the imageicon ?