Debian 9.4 + kernel backports - Cannot renew certificat

I can't open home-server.famille-bocquet.fr with my browser.

So http-01 - validation cannot work. A file under http://home-server.famille-bocquet.fr/.well-known/acme-challenge/xxxxxxxxxxxxxxxxxxxxxx must be global visible.

Is it possible to use dns-01 - validation?

Edit: There is a certbot-option:

./certbot-auto renew --preferred-challenges http

Use something like "dns" (I don't use certbot, so I don't know the exact option).