Wordpress. 301 redirects to another domain.

redirects.php

<?php
add_action( 'init', function () {
	// Exceptions (do not redirect these URIs)
	$exceptions = array(
		'/exception1',
		'/exception2',
	);
	
	// Redirects to special URIs
	$special_redirects = array(
		'/old-uri1' => 'https://newdomain.com/new-uri1',
		'/old-uri2' => 'https://newdomain.com/new-uri2',
	);

	$current_uri = $_SERVER['REQUEST_URI'];

	foreach ( $special_redirects as $old_path => $new_path ) {
		if ( str_contains( $current_uri, $old_path ) ) {
			wp_redirect( $new_path, 301 );
			exit();
		}
	}

	foreach ( $exceptions as $exception ) {
		if ( str_contains( $current_uri, $exception ) ) {
			return;
		}
	}

	// Redirects to the new domain
	wp_redirect( 'https://newdomain.com' . $current_uri, 301 );

	exit();
} );