I can't get a gas discount with a light car discount card, so why is that?

I got a discount card for a light car from Lotte Card.

I tried refueling, but when I checked the payment text, the amount I put in came out exactly.

I can't get a gas discount, do I have to apply separately to get a discount or something like that?

Or where should I register and write it?

990 2018-12-08 Gentleman

We'll get a discount on the bill later.

Gentleman 6 years ago 0

You'll get a discount on your bill later. So if you look at the invoice later, the discount will be printed on it.

Gentleman 6 years ago 0

Oh, that's how it was. Thank you for your reply.

Gentleman 6 years ago 0