Looking for KB to add Web Monitoring Zabbix 4.0.1

[wombat613]

When I set up the original server I must not have installed the Curl/PHP for web monitoring.

I do Configuration -> Hosts (or Templates) and there is no "Web" on the next line

Is it possible to do it after the fact? If so can I get a URL for the how to?

Thanks in advance.

T.