JS fetch print details of bad request response

Question

I am trying to use Django-rest-auth, I am getting it to work but often I get Bad request HTTP 400. In Django-rest-auth generated view I can see the details of the error (i.e username contains unaccepted chars or pwd do not match).

How can I get this information on frontend js side ? For now I was trying to just console the whole response but cannot find it in there

    const registerUser = async (user ) => {
      console.log( JSON.stringify(user))
      const response = await fetch("/api/dj-rest-auth/registration/", {
        method: "POST",
        headers: {
          "Content-Type": "application/json"
        },
        body: JSON.stringify(user)
      });

      if (response.status === 201) {
        console.log('did it ! !!! !! !!! ! !! ')
        let data = response.json()
        localStorage.clear();
        localStorage.setItem('authToken', data.key);

      } else {
        console.log(response);
      }
    };
    

Answer 1

Use try...catch as stated in comments by Konrad Linkowski.

const registerUser = async (user ) => {
      console.log( JSON.stringify(user))
   try {
      const response = await fetch("/api/dj-rest-auth/registration/", {
        method: "POST",
        headers: {
          "Content-Type": "application/json"
        },
        body: JSON.stringify(user)
      });

      if (response.status === 201) {
        console.log('did it ! !!! !! !!! ! !! ')
        let data = response.json()
        localStorage.clear();
        localStorage.setItem('authToken', data.key);

      } else {
        console.log(response);
      }
}catch (e){
console.log(e) // log the error , its an object so you can get desired error message
}
    };