cerficicates can be imported into oracle wallet, or java keystore.

option 1: import certificates into oracle wallet,

orapki wallet create -wallet <wallet_location> 

orapki wallet add 
  -wallet <wallet_location> 
  -trusted_cert -cert <certificate_location>

orapki wallet display -wallet <wallet_location> 

./okvutil upload -l "<wallet_location>" 
  -t wallet 
  -g "<virtual_wallet_name>"

option 2: import certificates into java keystore

keytool 
  -import 
  -trustcacerts 
  -alias <alias_name> 
  -file <cert_filename.crt> 
  -keystore <filename.jks>

keytool -list -v -keystore <filename.jks>

./okvutil upload -l "<keystore_location>" 
  -t jks 
  -g "<virtual_wallet_name>"