.acme folder is in root of file manager.
updatecert.sh in that folder is currently set up to request new certificates (anykeymail only for now).
To install the cert, navigate to the domain folder in the .acme folder.
Open a second tab with the SSLTLS Certificate control panel.
Copy the contents of the .cer file to the CRT field.
Copy the contents of the .key file to the KEY field.
Do not worry about the CABUNBLE field at this time.