I’ve received an email saying “You need to update your ACME client to use an alternative validation method (HTTP-01, DNS-01 or TLS-ALPN-01) before this date or your certificate renewals will break and existing certificates will start to expire.”.
But I didn’t find any article explaining how to implement this.
I’m using DigitalOcean droplet. Here’re other details:
Certbot version - 0.19.0
Ubuntu version - 16.04.3 LTS
Please share the command to perform this change.