MailChimp subscribe form with Angular 5 using jsonp

email-subscribe-form.component.ts

import { Component } from '@angular/core';
import { FormControl, Validators } from '@angular/forms';
import { HttpClient, HttpParams } from '@angular/common/http';

interface MailChimpResponse {
  result: string;
  msg: string;
}

@Component({
	selector: 'email-subscribe-form',
	templateUrl: './email-subscribe-form.component.html'
})
export class EmailSubscribeForm {

	submitted = false;
	mailChimpEndpoint = 'https://username.us6.list-manage.com/subscribe/post-json?u=abc123&id=123&';
	error = '';

	constructor(private http: HttpClient) { }

  // reactive form components
	emailControl = new FormControl('', [
		Validators.required,
		Validators.email,
	]);
	nameControl = new FormControl('', [
		Validators.required
	]);

	submit() {
		this.error = '';
		if (this.emailControl.status === 'VALID' && this.nameControl.status === 'VALID') {

			const params = new HttpParams()
				.set('NAME', this.nameControl.value)
				.set('EMAIL', this.emailControl.value)
				.set('b_123abc123abc123abc123abc123abc123abc', ''); // hidden input name

			const mailChimpUrl = this.mailChimpEndpoint + params.toString();

      // 'c' refers to the jsonp callback param key. This is specific to Mailchimp
			this.http.jsonp<MailChimpResponse>(mailChimpUrl, 'c').subscribe(response => {
				if (response.result && response.result !== 'error') {
					this.submitted = true;
				}
				else {
					this.error = response.msg;
				}
			}, error => {
				console.error(error);
				this.error = 'Sorry, an error occurred.';
			});
		}
	}
}

What to do if want to check using localhost?