Below two issues I was facing while trying to create ftps connection.
421 Sorry, cleartext sessions are not accepted on this server.
Uncaught No
protocol
found in connection credential
It was solved after some config changes, which I'm putting in the answer. Same should work for ftpes.
Tried this and worked (see "secure" and "secureOptions" specifically):
Note that "protocol" should always be "ftp" for ftp/ftps/ftpes.