The protocol used by Certbot is called ACME, and is supported by a bunch of CAs, both free and not. In addition to LE, there’s other CAs like sectigo, digicert

The protocol used by Certbot is called ACME, and is supported by a bunch of CAs, both free and not. In addition to LE, there’s other CAs like sectigo, digicert, and Google Trust Services that support it. A few are listed here: https://www.acmeisuptime.com/#CA-Software https://www.acmeisuptime.com/#CA-Software