Based on: https://github.com/jpmenil/zabbix-templates/isc-dhcp and https://github.com/garbled1/zabbix_isc_dhcpd

• install dependencies:
  • pip install pypureomapi
  • pip install netaddr
• mv userparameter_dhcp.conf /etc/zabbix/zabbix_agentd.d/
• mv check_dhcp_leases.py /usr/local/bin/
• Add lines like #= NAME =# to the end of all range statements, if you want.
• edit check_dhcp_leases.py to fix your omapi key and key name, also, probably the location of your dhcpd.conf file.

• import templates in zabbix

• Fix graphs name - I changed it to ip rate. It's more useful for me and protect from duplicate.
• Add support config dir conf.d
• Zabbix 4.x.x - tested from Zabbix 4.0.0 to Zabbix 4.4.5