Certbot failed to authenticate some domains (authenticator: standalone). The Certificate Authority reported these problems:
Domain: panel.stefanvasilescu.tk
Type: connection
Detail: 138.3.254.103: Fetching http://panel.stefanvasilescu.tk/.well-known/acme-challenge/LlnRzPUeA6Hr7-p1FWuU4BgaVVQhWbEAus20AYu-eVk: Timeout during connect (likely firewall problem)
#Help
3 messages · Page 1 of 1 (latest)
Self explanatory. You should actually read your error.
Tried everything and opened the ports...