Not Able to Connect my RDS Postgres sql for configuring application database

Hi Team,

I am trying to integrate Metabase and useing my Postgres RDS instance as the application database for Metabase, which is hosted on a container running on AWS ec2.
When the Metabase image and all required plugins are downloaded at the time of connection with my PostgreSQL, my container fails to connect to the database. I have declared the Environmental variable for the database.
so to verify the connectivity I am trying to telnet the DB it's connecting from the container.

Can Anyone Help me out ?

Please post the environment variables being used

environment:
MB_PLUGINS_DIR: /custom-plugins
MB_DB_TYPE: postgres
MB_DB_DBNAME: postgres
MB_DB_PORT: 5432
MB_DB_USER: metabaseapp
MB_DB_PASS: metabase@app
MB_DB_HOST: metabase-appdb.asdfg4lkjhg.ap-southeast-1.rds.amazonaws.com (Dummy)