get user id on payment process

Hi, I need to create a "fake" payment plugin that simply redirect user on registration end to a third party payment platform that need only the user id just created.
I'm thinking to make a copy of the offline plugin and insert my redirect on processPayment function by replacing this line:

JFactory::getApplication()->redirect(JRoute::_('index.php?option=com_osmembership&view=complete&Itemid=' . $Itemid, false, false));

Question: how can I get the user id before redirect call?
Thank you.

Hi Enrico

Use <?php echo $row->user_id; ?> you will get user_id of the subscriber

Regards,

Tuan