Hello,
You switch to the legacy mode ; it's not "working again", it's using the old HikaShop features which are now deprecated.
Please follow the instructions I gave you.
I didn't talk about any payment or shipping plugin ; I told you that it was a plugin, which mean a regular Joomla plugin !
www.hikashop.com/home/blog/357-hikashop-3-0-beta.html
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.