Extend Schema WordPress Plugin Knowledge Graph JSON-LD output https://schema.press/

schema-wp-knowledge-graph-json-extend.php

<?php //* do not include php tag

add_action('schema_wp_knowledge_graph_json', 'schema_wp_knowledge_graph_json_123456');
/**
 * Extend Schema Knowledge Graph JSON-LD output 
 *
 * @return schema json-ld array
 */
function schema_wp_knowledge_graph_json_123456( $schema ) {
	
	$schema['founder'] = "Founder Name"; // This can be a Person or Organization
	
	return $schema;
}