Services

listen {
        ip *;
        port 6697;
        options { tls; }
        tls-options {
                certificate "/home/ircd/.acme.sh/irc.letspiss.net/fullchain.cer";
                key "/home/ircd/.acme.sh/irc.letspiss.net/irc.letspiss.net.key";
        };
}

Note: Do not change the certificate key for the serversonly listen block or your spkifp will change and you won't be able to link to the network.