Let's Encrypt is a CA and from the moment the EFF took over development of Certbot, does not develop any ACME client. As far as I know, Let's Encrypt does not block the .ir TLD.
Please note that the Certbot team is discontinuing Windows support. See Certbot Discontinuing Windows Beta Support in 2024 for more information.
You can see a (probably non-exhaustive) list of ACME clients at ACME Client Implementations - Let's Encrypt, including for Windows.