How to change to search label for the store locator

The store locator’s first field, by default, is labelled with: Enter your postal code, city and / or state 

As of version 7.5 of Yoast SEO: Local, this label can be customized using the developer filter: yoast-local-seo-search-label.

add_filter( 'yoast-local-seo-search-label', function( $search_label ) {
  $search_label = 'Your new search label';

  return $search_label;
} );