How to extend the subscription expiration date

-- HikaShop version -- : 5.0.4
-- HikaSerial version -- : 4.0.2
-- Joomla version -- : 4.2.9
-- PHP version -- : 8

Hi, I use Hikaserial to sell subscriptions with Hikashop and organize email marketing automations using Acymailing Follow Up. I would like to extend the expiration of a subscription for a specific user by two months. When I open this user's subscription in Hikaserial, I see a field with the end date of the subscription and another field called extra data.
Is it enough that I change the date in the end date field or do I have to use extra data or do I have to follow another method?
Thanks
Francesco

Thank you
Best regards
Francesco