Jitsi on Ubuntu Server 19.10 (local vm in esxi) + DNS set in Siteground. Problem with Let's Encrypt

Hi,
i’ve installed a ubuntu server 19.10 vm in my esxi in local. After that i put a DNS in my siteground account to resolve my Public IP of my line and i’ve also open 80 and 443 ports on my pfsense firewall to redirect all the traffic from public ip to a isolated VM where jitsi server is installed.
In local all works fine but, when in a installation procedure i reach the line to create a let’s encrypt certificate, i receive the error:

IMPORTANT NOTES:

  • The following errors were reported by the server:

    Domain: conference.mybuzi.com
    Type: connection
    Detail: Fetching

    Timeout during connect (likely firewall problem)

    To fix these errors, please make sure that your domain name was
    entered correctly and the DNS A/AAAA record(s) for that domain
    contain(s) the right IP address. Additionally, please check that
    your computer has a publicly routable IP address and that no
    firewalls are preventing the server from communicating with the
    client. If you’re using the webroot plugin, you should also verify
    that you are serving files from the webroot path you provided.

  • Your account credentials have been saved in your Certbot
    configuration directory at /etc/letsencrypt. You should make a
    secure backup of this folder now. This configuration directory will
    also contain certificates and private keys obtained by Certbot so
    making regular backups of this folder is ideal.

What can i do to create a local VM with Jitsi and have a valid HTTPS certificate?

My scope is to create a link on my website like: hxxps://conference.mywebsite.com that point to hxxps://publicipofmyline:443 (that reach VM in local server ESXI) and have a valid HTTPS certificate

Where i did wrong?

Ah… i used this guide: htxx://www.vultr.com/docs/how-to-install-jitsi-meet-on-ubuntu-18-04-lts
and i add the line in hosts:

sudo hostnamectl set-hostname conference
sudo sed -i 's/^127.0.1.1.*$/127.0.1.1 conference.mywebsite.com conference/g' /etc/hosts

and when in installation the script ask me to put a localdomain i put: conference.mywebsite.com

Where i did wrong?
What can i do for resolve that?

I solved by doing a certificate in my PFSense with ACME Certificate package and Let’s Encrypt + add a DNS in my Domain in Siteground