Any web interface would be a third-party enhancement; as LE only interacts via ACME protocol.
So, does one exist?
Yes.
Would you mention one here?
No.
Why?
Because I don't want to sound like I am recommending any of them (which I don't).
If your need of a cert is for a tight system like Godaddy shared hosting, there is a PHP client for that.
See: CertSage ACME client (version 1.0.0) - easy webpage interface, no commands to type, root not required