How to register a block template with an ACF Custom Block and pre-populate it's ACF fields.

acf-block-template.php

<?php
function register_csg_patterns() {
}
 
add_action( 'init', 'register_csg_patterns' );

function myBlockTemplate() {
	$myBlockTemplate = get_post_type_object( 'myCustomPostType' ); // Adds these blocks to a specific post type
	$myBlockTemplate->template = array(

		array( 'acf/csg-group', // use 'acf/myBlockSlug' to call you custom block
			array( "data" => 
				array(
          // In addition to core block properties, this array can store ACF custom block properties.
          // Each of the custom fields used here are button group fields, which need a specific value to be antered for it to work.
					"align"	=>	"wide", // THis is the core block width setting
					"background_color"	=>	"transparent", // Use ACF field slug and a corresponding value
					"height"	=>	"medium",
					"style"	=>	"halftone-bottom-left",
				),
			),
			array(
        // This ACF block uses InnerBlocks. Child blocks go here.
				array( 'core/paragraph', 
					array( 
						'content' => 'Add a brief job description here.'
					)
				),
			)
		),
		array( 'core/heading', array( 
			'level' => 2, 'content' => 'Duties' ) ),
		array( 'core/paragraph' ),
		array( 'core/heading', array( 
			'level' => 2, 'content' => 'Qualifications' ) ),
		array( 'core/list' ),
		array( 'core/heading', array( 
			'level' => 2, 'content' => 'Physical Requirements' ) ),
		array( 'core/list' ),

	);
}
add_action( 'init', 'careers_template' );
?>