Not able to connect to public postgres from EC2

Question

I wanted to connect to a public postgres from my EC2 machine but not able to establish a connection. I have added a outbound rule for postgress port 543 but no luck so far.

Below is the details of the postgress i am trying to connect.

conn = psycopg2.connect(
    host="hh-pgsql-public.ebi.ac.uk",
    database="pfmegrnargs",
    user="reader",
    password="NWDMCE5xdipIjRrp")

Also attached is the outbound rule and error message for reference.

Appreciate all your help !!