I cannot emit a SSL certificate from Linode tutorial

I'm following this tutorial Secure a Website or Domain with Let's Encrypt and acme.sh, and I'm at section Issue a certificate, step 2. When running this command:

acme.sh --issue --dns dns_linode_v4 --dnssleep 90 -d any-name.org -d *.any-name.org

Note: my domain name has a hyphen.

I'm getting this message:

[Sun Apr  3 20:34:43 PET 2022] Using CA: https://acme.zerossl.com/v2/DV90
[Sun Apr  3 20:34:43 PET 2022] Create account key ok.
[Sun Apr  3 20:34:43 PET 2022] No EAB credentials found for ZeroSSL, let's get one
[Sun Apr  3 20:34:43 PET 2022] acme.sh is using ZeroSSL as default CA now.
[Sun Apr  3 20:34:43 PET 2022] Please update your account with an email address first.
[Sun Apr  3 20:34:43 PET 2022] acme.sh --register-account -m my@example.com
[Sun Apr  3 20:34:43 PET 2022] See: https://github.com/acmesh-official/acme.sh/wiki/ZeroSSL.com-CA
[Sun Apr  3 20:34:43 PET 2022] Please add '--debug' or '--log' to check more details.
[Sun Apr  3 20:34:43 PET 2022] See: https://github.com/acmesh-official/acme.sh/wiki/How-to-debug-acme.sh

what does ZeroSSL has to do with this process? What happened with Let's Encrypt? is this tutorial outdated? What should I do?

UPDATE 1:

I've run this command:

$ acme.sh --set-default-ca --server letsencrypt 

And tried to emit a certificate again, but I get this message:

$ acme.sh --issue --dns dns_linode_v4 --dnssleep 90 -d any-name.org -d *.any-name.org
[Sun Apr  3 23:12:26 PET 2022] Please refer to https://curl.haxx.se/libcurl/c/libcurl-errors.html for error code: 60
[Sun Apr  3 23:12:26 PET 2022] Can not init api for: https://acme-v02.api.letsencrypt.org/directory.
[Sun Apr  3 23:12:26 PET 2022] Sleep 10 and retry.
[Sun Apr  3 23:12:37 PET 2022] Please refer to https://curl.haxx.se/libcurl/c/libcurl-errors.html for error code: 60
[Sun Apr  3 23:12:37 PET 2022] Can not init api for: https://acme-v02.api.letsencrypt.org/directory.
[Sun Apr  3 23:12:37 PET 2022] Sleep 10 and retry.

No help about this message on Internet.