Get primary category

Hi, I’m trying to figure out if “Primary category term” is a Rank Math option. And I think so.

How do I insert primary category term in a php file where the various categories of a post are called. Then replace all categories, only with the primary category.

This is the post block code (if it can be useful):

case 'cats-alt':
if ( 'post' == get_post_type() ) {
$categories = get_the_category();
$categories_list = '';
if($categories){
								foreach($categories as $cat) {
									$categories_list .= wp_sprintf( '<a href="%s" title="%s" class="cat-tag bg-by-cat %s"><span>' . $cat->cat_name . '</span></a>',
										esc_url( get_category_link( $cat->term_id ) ), 
										esc_attr( wp_sprintf( _x( "View all posts in %s", 'entry-meta: post cat(s) title attribute', 'wp-post-blocks' ), $cat->name ) ),
										$cat->slug,
										esc_html( $cat->cat_name )
									);
								}
echo wp_sprintf( '<span class="cat-links meta-info">%s</span>', $categories_list );
							}
						}
break;

Thanks for the support