How to change data on the server?

Question

JSON

Good afternoon! I am working on one web application on a fake "Json - server".
I had such a problem, because I'm using the PATCH method for the first time, I can't change the data on the server, it gives a 400 error in the console, and the browser gives the error "TypeError: Cannot read property 'type' of undefined".
I'll attach the code below

.

export const editChannel = (name, login, link, followers, desk, id) => {
  fetch(`http://localhost:3001/channels/${id}`,{
    method: 'PATCH',
    body: {
      name: name,
      channelLogin: login,
      imgUrl: link,
      followers: followers,
      desk: desk
    },
    headers: {
      'Content-type': 'application/json; charset=UTF-8'
    },
  })
    .then(res => res.json())
    .then(json => {
      console.log(json)
    })
}