How can I connect Digi XBee3 PRO Zigbee 3.0 to Raspberry pie zero?

Hi, I’m a novice developer with bare minimal knowledge about XBee and RPi. This is my first project where I have to use a battery operated RPi zero to collect very small IR image and transmit it via ZigBee (BT or WiFi can’t be used because of power constraints) over a considerable range. Hence I’m going with RPi zero for low power consumption and XBee3PRO for better range. I’m stuck up with communication between RPi and XBee3 PRO ZigBee 3.0

  1. Is it possible to communicate between XBee3 and Raspberry pie zero witout using any shields via UART interface
  2. How can I use SPI interface for communication between XBee3 and RPi with or without any shields

Please help me go forward.