Certbot failed to renew my cert

Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. crt.sh | example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.

My domain is: www.mono500.com

I ran this command: certbot renew --force-renewal

It produced this output:
Attempting to renew cert (mono500.com) from /etc/letsencrypt/renewal/mono500.com.conf produced an unexpected error: HTTPSConnectionPool(host='acme-v01.api.letsencrypt.org', port=443): Max retries exceeded with url: /directory (Caused by NewConnectionError('<urllib3.connection.VerifiedHTTPSConnection object at 0x7fe495ae8198>: Failed to establish a new connection: [Errno -2] Name or service not known',)). Skipping.
All renewal attempts failed. The following certs could not be renewed:
/etc/letsencrypt/live/mono500.com/fullchain.pem (failure)

My web server is (include version): nginx/1.16.1

The operating system my web server runs on is (include version): Ubuntu 18.04.3

My hosting provider, if applicable, is: OVH

I can login to a root shell on my machine (yes or no, or I don't know): yes

I'm using a control panel to manage my site (no, or provide the name and version of the control panel): no

The version of my client is (e.g. output of certbot --version or certbot-auto --version if you're using Certbot): 0.23.0

A few things:

Please don't use this option if you don't understand it. Better even: never use any option you don't understand. --force-renewal won't magically renew a certificate if there is an issue with issuance to begin with.

Certbot 0.23.0 is VERY old. Please update your Certbot.

The ACMEv1 API is down for a long time now. Thus it makes sense you're getting a DNS error: the hostname doesn't exist any longer.

I believe modern Certbots can handle this automatically. Please update Certbot and check if renewal works again.