Svelte

<script>
  let sent = false;
  let error = "";

  async function submit(event) {
    const body = new FormData(event.currentTarget);
    body.append("access_key", "YOUR_ACCESS_KEY_HERE");

    const res = await fetch("https://api.formpost.ai/submit", {
      method: "POST",
      headers: { Accept: "application/json" },
      body,
    });

    const result = await res.json();
    if (result.success) sent = true;
    else error = result.message;
  }
</script>

<form on:submit|preventDefault={submit}>
  <input name="name" required />
  <input type="email" name="email" required />
  <textarea name="message" required></textarea>
  <button type="submit">Send</button>
  {#if sent}<p>Thanks — we will be in touch.</p>{/if}
  {#if error}<p>{error}</p>{/if}
</form>