acf.php

<?php
/**
 * Advanced Custom Fields
 *
 * @package      KatieWorkman2020
 * @author       Bill Erickson
 * @since        1.0.0
 * @license      GPL-2.0+
**/

class BE_ACF_Customizations {

	public function __construct() {

		// Register options page
		add_action( 'init', array( $this, 'register_options_page' ) );

		// Register Blocks
		add_action('acf/init', array( $this, 'register_blocks' ) );

	}

	/**
	 * Register Options Page
	 *
	 */
	function register_options_page() {
	    if ( function_exists( 'acf_add_options_page' ) ) {
	        acf_add_options_page( array(
	        	'title'      => __( 'Site Options', 'katieworkman2020' ),
	        	'capability' => 'manage_options',
	        ) );
	    }
	}

	/**
	 * Register Blocks
	 * @link https://www.billerickson.net/building-gutenberg-block-acf/#register-block
	 *
	 * Categories: common, formatting, layout, widgets, embed
	 * Dashicons: https://developer.wordpress.org/resource/dashicons/
	 * ACF Settings: https://www.advancedcustomfields.com/resources/acf_register_block/
	 */
	function register_blocks() {

		if( ! function_exists('acf_register_block_type') )
			return;

    acf_register_block_type( array(
			'name'				=> 'testimonial',
			'title'				=> __( 'Testimonial', 'katieworkman2020' ),
			'description'		=> __( 'Displays one testimonial. Manage testimonials in Site Options', 'katieworkman2020' ),
			'render_template'	=> 'partials/block-testimonial.php',
			'category'			=> 'widgets',
			'icon'				=> 'editor-quote',
			'mode'				=> 'preview',
			'keywords'			=> array( 'quote' ),
		));
	}

}
new BE_ACF_Customizations();

block-testimonial.php

<?php
/**
 * Testimonial block
 *
 * @package      KatieWorkman2020
 * @author       Bill Erickson
 * @since        1.0.0
 * @license      GPL-2.0+
**/

$testimonials = get_field( 'ea_testimonials', 'option' );
if( empty( $testimonials ) )
	return;

$testimonial = $testimonials[ array_rand( $testimonials ) ];
echo '<blockquote class="is-style-testimonial">' . wpautop( $testimonial['quote'] );
if( !empty( $testimonial['byline'] ) )
	echo ' <cite>' . $testimonial['byline'];
echo '</blockquote>';