Personalise Email Subject

-- HikaShop version -- : 6.5.2 [2608261812]
-- Joomla version -- : 6.1.3
-- PHP version -- : 8.4.24

Some customers order emails going to junk due to their server settings

Lots of testing has finally resolved that having their name in the email subject resolves the issue

How to customize the subject line in the Language File to achieve that?