Zero Online Worker on bench doctor

Hello !!

I am facing an issue with sent email is not displayed in the Email queue. then I run a bench worker. all sent mail is started coming in the email queue.

But I found there is 0 online worker by running bench doctor.

I tried by reboot the server.

I am running on AWS with bitnami stack.

version

ERPNext: v12.12.0 (version-12)

Frappe Framework: v12.10.0 (version-12)

so how to deal with this?