[standalone@embedded /] /subsystem=elytron/secret-key-credential-store=p:add(path=x/y,create=true)
{
    "outcome" => "failed",
    "failure-description" => {"WFLYCTL0080: Failed services" => {"org.wildfly.security.credential-store.p" => "WFLYELY00004: Unable to start the service.
    Caused by: org.wildfly.security.credential.store.CredentialStoreException: ELY09513: Unable to flush credential store to storage
    Caused by: java.io.FileNotFoundException: /home/okotek/test/server/x/y (No such file or directory)"}},
    "rolled-back" => true
}

[standalone@embedded /] /subsystem=elytron/credential-store=p:add(location=x/y,create=true,credential-reference={clear-text=p})
{"outcome" => "success"}