Hi,
Thanks for your feedback. You must be on PHP 8.2
Please note that this is not an error. This is a message from PHP to developers to let them know that in the next version of PHP, something will change which will generate an error if the code is not changed.
Normally, that message should not appear on a production website. So I would recommend turning off the "error reporting" setting of the Joomla configuration, or properly configuring the php.ini of the server to not output deprecation messages.
Of course, we're going to change the code to not have the deprecation message so that HikaShop won't get an error there on PHP9. The change is quite simple, it consists on adding the line:
public $geolocation;
before the line:
function __construct(&$subject, $config){
in the file plugins\system\hikashopgeolocation\hikashopgeolocation.php