Try some tutorials like this:
https://randomnerdtutorials.com/how-to-install-esp8266-board-arduino-ide/
Sketch -> Include Library -> Manage Libraries...
Install library "OneWire"
Install library "DallasTemperature"
ZABBIXAGHOST is Hostname in Zabbix system e.g.: ESP
ZABBIX_KEY is Key in Zabbix system e.g.: ServerRoom