Can iPhone XR be upgraded to receive 5G

No, an iPhone XR does not have the proper hardware to operate on the 5G band frequencies.

No, if you are asking about 5G cellular.

• Model A1984*
  • FDD‑LTE (Bands 1, 2, 3, 4, 5, 7, 8, 12, 13, 14, 17, 18, 19, 20, 25, 26, 29, 30, 32, 66, 71)
  • TD‑LTE (Bands 34, 38, 39, 40, 41)
  • CDMA EV-DO Rev. A (800, 1900 MHz)
  • UMTS/HSPA+/DC-HSDPA (850, 900, 1700/2100, 1900, 2100 MHz)
  • GSM/EDGE (850, 900, 1800, 1900 MHz)
• All models
  • LTE Advanced4
  • 802.11ac Wi‑Fi with 2x2 MIMO
  • Bluetooth 5.0 wireless technology
  • NFC with reader mode
  • Express Cards with power reserve