Good reference for the HARDWARE PART ONLY: https://ava.upuaut.net/?p=951 if you use this board. Stop when you get to "Enabling PPS/ATOM support in NTPD." and skip down to "Setting stationary mode."
Other hardware guides include https://blog.webernetz.net/ntp-server-via-gps-on-a-raspberry-pi/
and https://robrobinette.com/pi_GPS_PPS_Time_Server.htm but follow the hardware setup section only,
including editing your /boot/cmdline.txt, /boot/config.txt and /etc/modules files.