Users Api errors not localized


When I try to add a user that already exists, Keycloak returns

{“errorMessage”:“User exists with same username”}

I had set the theme default locale to [ja] for master realm and for the test tenant.
Also, I had set the user locale to [ja] for the master admin user.

On other hand, if I create a password policy and try to reset the password using a password that does not meet the policy, I get the error message in the correct locale.

{error=invalidPasswordMinLengthMessage, error_description=無効なパスワード: 最小4の長さが必要です。}

Is any way to get the users API error messages translated?