I have successfully launched new AWS RDS PostgreSQL v10 instance and need to install PostgreSQL v10 client on Amazon Linux EC2 instance.
I have tried to install
PGDG repo is no longer available for Amazon Linux. So you can use amazon repo.
amazon-linux-extras install postgresql10 vim epel -y
Or follow this article
https://installvirtual.com/install-postgresql-10-on-amazon-ec2/