Hi, @Vinodh Ramadurai Welcome to Microsoft Q&A Thanks for posting your query.
As we understand the ask here is you want to know how to use the job pg_dbms_job package present in PostgreSQL 11 version.
Unfortunately, we do not support pg_dbms_job, we do support pg_corn. you can refer to more details on pg_corn here.
These are the lists for both flex and single you can also refer to these documents for Single server and flexible server extensions
as you see pg_cron is supported only on a flexible server.
Please let us know if the information helps.
Regards
Geetha