can't add ECDSA certificate key when signing CSR
If you try to sign CSR it not allow to add Key data with following errors:
The following input errors were detected: This private does not appear to be valid. Key data field should be blank, or a valid x509 private key
it is ok it you add only CSR, without ec key data.
it is ok if you import existing certificate and ec-key with "Import an existing Certificate"
key created with:
openssl ecparam -name brainpoolP160r1 -genkey -param_enc explicit -out ec-ovpns.pem
openssl req -key ec-ovpns.pem -new -out ec-ovpns.csr