Lets encrypt failed

I’ve been using nc for long time until i changed isp and the new isp refused to open port 80. From that time i cannot use nc out of private network.

When i try to get letsencrypt work i get the following message :
[ letsencrypt ] (Sun Dec 13 14:49:40 GMT 2020)
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Plugins selected: Authenticator webroot, Installer None
Obtaining a new certificate
Performing the following challenges:
http-01 challenge for ptoussis.servehttp.com
Using the webroot path /var/www/nextcloud for all unmatched domains.
Waiting for verification…
Cleaning up challenges
Failed authorization procedure. ptoussis.servehttp.com (http-01): urn:ietf:params:acme:error:connection :: The server could not connect to the client to verify the domain :: Fetching http://ptoussis.servehttp.com/.well-known/acme-challenge/ccXQLAojNT64sUqRLeUBJKI2tF-TIONfVNlWeK5XM9I: Timeout during connect (likely firewall problem)
IMPORTANT NOTES:
- The following errors were reported by the server:

Domain: ptoussis.servehttp.com
Type: connection
Detail: Fetching
http://ptoussis.servehttp.com/.well-known/acme-challenge/ccXQLAojNT64sUqRLeUBJKI2tF-TIONfVNlWeK5XM9I:
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.

Let’s encrypt requires access to port 80/tcp (http-01) to verify that a domain for which you’re going to request a certificate is owned by you. Unfortunately if an inbound port 80/tcp connection cannot be established is isn’t possible to use this service with that protocol.