Is there a different UNNI app for foreigners?

I’m speaking with Shinsang about double chin lipo, and I mentioned that I saw a lower price on UNNI. At first they said they could apply the promotional price for me, but asked for a screenshot. When I sent it, this was their response:

“I think you are looking at the Korean/local UNNI app which is only for Korean citizens who live here. unless you have a foreigner's card, this price will not apply to you. sorry.”

I’ve seen a few people here saying they’ve booked through UNNI so I’m wondering how they did it.

Thank you!