Register Custom Post Type

cpt.php

<?php
$args = array(

  'template' => array(
    array( 'core/heading', array(
      'placeholder' => 'Payment Options',
      'content' => 'Payment Options',
    ) ),
    array( 'acf/custom-block' ),
    array( 'core/heading', array(
      'placeholder' => 'Payment Note(s)',
      'content' => 'Payment Note(s)',
      'level' => 3,
  ),
);