This happens even in other online casinos—you won’t see certain games if they don’t have a license to operate in your area, like in my case here in the Philippines.
For example, I want to play PlayNGO slots on sites like Sportsbet.io or Livecasino.io, but they’re not available to me. However, players in other regions can play them.

You’ll only be able to play slots from that provider once they get a license to operate in your area. Or they allowede to use VPN and select area that PlayNGO is playable.