i would do that using a .htaccess redirect rule, but if you want a laravel way, i think this should cover it.
Route::domain('example3.com')
->group(function () {
Route::any('{any}', function () {
return redirect()->away('https://www.example1.com' . request()->getRequestUri(), 301);
});
});
here is the .htaccess approach:
RewriteEngine on
RewriteCond %{HTTP_HOST} ^(www\.)?example3\.com$ [NC]
RewriteRule ^(.*)$ https://www.example1.com/ [R=301,L]