How can I create the recipe schema by automatically taking data from ACF PRO?

Hello,

Thank you for contacting Rank Math for help with automating the addition of custom variables to your recipe schema.

You may need to create custom schema using the Rank Math filter to extend JSON+LD data:

/**
 * Collect data to output in JSON-LD.
 *
 * @param array  $unsigned An array of data to output in json-ld.
 * @param JsonLD $unsigned JsonLD instance.
 */
add_filter( 'rank_math/json_ld', function( $data, $jsonld ) {
	return [];
}, 99, 2);

With Rank Math PRO you can create custom schema templates along with custom schema variables. You can check the following article on schema templates: https://rankmath.com/kb/schema-templates/

Hope that helps. Please let us know if you have questions.