Step1: Download and install psql tool from https://www.postgresql.org/download/ for your version of OS.
For Linux:
sudo yum install -y https://download.postgresql.org/pub/repos/yum/reporpms/EL-7-x86_64/pgdg-redhat-repo-latest.noarch.rpm sudo yum install postgresql14
Step2: Copy the endpoint, database name, port information from AWS Management console for your Redshift database and use the below connection string to connect to the database. You will be prompted to enter the password for your specified ‘username‘.
psql -h<endpoint>-U<username>-d<databasename>-p<port>