Define ACME Servers locations for Certs request

1. The problem I’m having:

I want to restrict incoming traffic to my network from the GeoIP white list in my firewall. As I have no requirements to allow incoming connections from USA, I want to block this country as well. (Current log analysis shows that most traffic to brute-force known vulnerabilities comes from CN, USA and ru)
My problem however is that Caddy is requesting new certificates from ACME servers and I am getting requests from USA ACME servers which do not work if I block USA incoming traffic.

2. Error messages and/or full log output:

Error message is clear, where ACME says that it can not reach my server thus could not issue cert.

3. Caddy version:

v2.9.1

4. How I installed and ran Caddy:

a. System environment:

Debian, Proxmox, LXC container

b. Command:

/usr/bin/caddy run --environ --config /etc/caddy/Caddyfi

c. Service/unit/compose file:

[Unit]
Description=Caddy
Documentation=https://caddyserver.com/docs/
After=network.target network-online.target
Requires=network-online.target

[Service]
Type=notify
User=caddy
Group=caddy
ExecStart=/usr/bin/caddy run --environ --config /etc/caddy/Caddyfile
ExecReload=/usr/bin/caddy reload --config /etc/caddy/Caddyfile --force
TimeoutStopSec=5s
LimitNOFILE=1048576
PrivateTmp=true
ProtectSystem=full
AmbientCapabilities=CAP_NET_ADMIN CAP_NET_BIND_SERVICE

[Install]
WantedBy=multi-user.target

d. My complete Caddy config:

mysrv1 {
        reverse_proxy 192.168.x.x:pppp
}

mysrv2 {
        reverse_proxy 192.168.x.x:pppp
}

mysrv3 {
        handle {
                reverse_proxy 192.168.x.x:pppp {
                        header_down Strict-Transport-Security "max-age=15552000; includeSubDomains"
                }
        }
}

5. Links to relevant resources:

Check the documentation on configuring a different ACME provider, if you found one in a nation more to your preferences. Buypass, perhaps? Another alternative might be using DNS challenges which would let you to keep your Caddy server entirely inaccessible.