30 - Failed Missing Field Merchant ID

-- HikaShop version -- : 3.2.1
-- Joomla version -- : 3.8.2
-- PHP version -- : 7.1.12
-- Browser(s) name and version -- : Firefox Quantum 57.0
-- Error-message(debug-mod must be tuned on) -- : 30 - Failed Missing Field Merchant ID

I'm creating a custom payment method using example plugin, but during checkout, I get an error 30 - Failed Missing Field Merchant ID.

Has anyone encountered this? Can someone help? Where should this field be?

Hello,

It looks like a message from the payment gateway system.
So I think it's coming from your custom plugin.

Regards,