ipfilter is a middleware for Caddy

ipfilter / {
	rule block
	ip 192.168 213.42.9.10-50 214.1.1.10
}

caddy will block any clients with IPs that fall into one of these two ranges 192.168.0.0 to 192.168.255.255 and 213.42.9.10 to 213.42.9.50 , or a client that has an IP of 214.1.1.10 explicitly, ranges are inclusive, which means 213.42.9.50 will get blocked.

ipfilter / {
	rule allow
	blockpage default.html
	ip 55.3.4.20 55.3.4.30
}

caddy will serve only these 2 IPs, eveyone else will get default.html

filtering with country codes requires a local copy of the Geo database, can be downloaded for free from MaxMind

ipfilter / {
	rule allow
	database /data/GeoLite.mmdb
	country US JP
}

with that in your Caddyfile caddy will only serve users from the United States or Japan

ipfilter /notglobal /secret {
	rule block
	database /data/GeoLite.mmdb
	blockpage default.html
	country US JP
}

having that in your Caddyfile caddy will ignore any requests from United States or Japan to /notglobal or /secret and it will show default.html instead, blockpage is optional.

ipfilter / {
	rule allow
	ip 32.55.3.10
}

ipfilter /webhook {
	rule allow
	ip 131.133.10
}

You can use as many ipfilter blocks as you please, the above says: block everyone but 32.55.3.10, Unless it falls in the range 131.133.10.0-131.133.10.255 and requesting a path in /webhook