Loading animation avec Axios (react.js)

  handleSubmit(event) {
    if (this.state.email === this.state.email02  && this.state.passwd === this.state.passwd02 && this.state.lastname !== '') {
      const data = {email: this.state.email, passwd: this.state.passwd, lastname: this.state.lastname, firstname: this.state.firstname}

      axios.post('http://XXX.XX.XX.192:XXXX/register', data)
      .then(
        response => {console.log(response);
        this.props.history.push('/SignIn');
        alert('You are almost one of us, click on the verification link sent by email to complete your registration.');
      })
      .catch(err => {console.log(err);})
    } else if (this.state.email !== this.state.email02 ) {
        console.log('email are not the same');
        alert('email are not the same !');
    } else if (this.state.passwd !== this.state.passwd02) {
        console.log('password are not the same');
        alert('password are not the same !');
    } else {
      console.log('Unknown Error');
      alert('Unknown Error, please try again later');
    }
  }