No serializers associated with the filename or extension for generating json changelog

General Discussion
1

$LIQB_HOME/liquibase --driver=oracle.jdbc.OracleDriver </div>

      --classpath=ojdbc7.jar </div>

      --changeLogFile=work/ChangeLogs/hr_$dt.json </div>

      --url=“jdbc:oracle:thin:@vbox2:1521/pdbpoc” </div>

      --username=hr </div>

      --password=oracle </div>

      --changeSetAuthor=rluo </div>

      generateChangeLog

when I generate json format change log, I am getting below error, any suggestions will be highly appreciated.

Unexpected error running Liquibase: java.lang.RuntimeException: No serializers associated with the filename or extension ‘work/ChangeLogs/hr_201908270146.json’

liquibase.exception.LiquibaseException: liquibase.command.CommandExecutionException: java.lang.RuntimeException: No serializers associated with the filename or extension ‘work/ChangeLogs/hr_201908270146.json’

... 4 common frames omitted</div></div>