Another free CA as an alternative to Let's Encrypt
This looks like it's only for personal and non-public certs in a commercial context.From their Terms and Conditions:" ZeroSSL is for your personal or internal business use only and must be in compliance with all applicable ZeroSSL policies, laws, rules and regulations. As well as this, no third party rights can be violated or infringed upon through use of ZeroSSL. You may not use ZeroSSL for any commercial purpose including but not limited to selling, licensing, providing services, or distributing ZeroSSL to any third party unless you have received the express written consent of ZeroSSL beforehand."https://zerossl.com/terms/