Hello
go to dashboard >> appearance >> theme editor >> on the right side expand the inc folder >> find the functions.php inside it, folder destination =>> inc/functions.php >> click on it to open >> go to line no. 323 you will see the given code below in it

$args = array(‘post_type’ => ‘lz_fitness_testimoni’);

change the lz_fitness_testimoni as per your requirement >> click on save changes button at the bottom

Thank you