Going to Settings>General>About>Model and tapping on it you should see a number like A1864, A1897, A1898. (it should be A1897)
Then read the possible model numbers that can work in the country you're in:
iPhone - View countries with supported LTE networks - Apple
You can also visit an Apple Store or Authorized service provider and ask them (find the country among this list):
Apple - Find Locations - Location Selector
Regards
Giulio