I can't run elasticsearch on my vps Ubuntu 20.04

Question

I have a big problem with Elasticsearch am trying to configure basic security on my Elasticsearch production but i'm getting error when i try to launch a command from the path /usr/share/Elasticsearch/bin i'm getting this error...

    ./elasticsearch-env: line 88: /etc/default/elasticsearch: Permission denied

All the directories is owned by the right user and group (elasticsearch:elasticsearch)
Then when i try to run the command as sudo, i get this error

    OpenJDK 64-Bit Server VM warning: Option UseConcMarkSweepGC was deprecated in version 9.0 and will likely be removed in a future release.
[2022-02-11T14:43:15,503][ERROR][o.e.b.ElasticsearchUncaughtExceptionHandler] [arkoosnode] uncaught exception in thread [main]
org.elasticsearch.bootstrap.StartupException: java.lang.RuntimeException: can not run elasticsearch as root
        at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:170) ~[elasticsearch-7.16.3.jar:7.16.3]
        at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:157) ~[elasticsearch-7.16.3.jar:7.16.3]
        at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:77) ~[elasticsearch-7.16.3.jar:7.16.3]
        at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:112) ~[elasticsearch-cli-7.16.3.jar:7.16.3]
        at org.elasticsearch.cli.Command.main(Command.java:77) ~[elasticsearch-cli-7.16.3.jar:7.16.3]
        at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:122) ~[elasticsearch-7.16.3.jar:7.16.3]
        at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:80) ~[elasticsearch-7.16.3.jar:7.16.3]
Caused by: java.lang.RuntimeException: can not run elasticsearch as root
        at org.elasticsearch.bootstrap.Bootstrap.initializeNatives(Bootstrap.java:107) ~[elasticsearch-7.16.3.jar:7.16.3]
        at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:183) ~[elasticsearch-7.16.3.jar:7.16.3]
        at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:434) ~[elasticsearch-7.16.3.jar:7.16.3]
        at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:166) ~[elasticsearch-7.16.3.jar:7.16.3]
        ... 6 more
uncaught exception in thread [main]
java.lang.RuntimeException: can not run elasticsearch as root
        at org.elasticsearch.bootstrap.Bootstrap.initializeNatives(Bootstrap.java:107)
        at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:183)
        at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:434)
        at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:166)
        at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:157)
        at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:77)
        at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:112)
        at org.elasticsearch.cli.Command.main(Command.java:77)
        at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:122)
        at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:80)
For complete error details, refer to the log at /var/log/elasticsearch/elasticsearch.log
2022-02-11 14:43:15,874409 UTC [3267] INFO  Main.cc@111 Parent process died - ML controller exiting

Could you help me to resolve that, please..
Thanks for your attention. I’m looking forward to your reply.
If you need more informations, tell me ;)