Nighthawk 5G router LTE band support (MR5200-100EUS)

Hello, I am now looking for 5G+LTE Wi-Fi router.

Does Nighthawk 5G MR5200-100EUS has support for LTE band 5? (850Mhz)

I am now living in Korea and LTE band 5 is really essential for wide range cellular coverage, including rural areas and parking lots.

Is there any way to unlock the band 5 by using some command line script or adding external antennas?