Reverse proxy for php-fpm

1. Caddy version (2.4.2):

Hi, everyone!
I’m setting up a reverse proxy for php-fpm.
A request to php-fpm is passed, but it is refilled at php-fpm /srv. What am I doing wrong?

My Caddyfile:

{
    auto_https off
}
http://myexternalhostname:8080 {
			reverse_proxy myphpfpmhost:9000 {
											transport fastcgi
									         	header_up X-Real-IP {remote_host}
											}
}

log from php-fpm host:

172.18.0.4 -  19/Jun/2022:12:15:20 +0000 "GET " 403
NOTICE: Access to the script '/srv' has been denied (see security.limit_extensions)

That’s an outdated version. Please upgrade to v2.5.1.

Are you sure you’re not looking for the php_fastcgi directive?

Either way, you need to set root for Caddy to know how to construct the path to the files on disk.