Configuring newrelic for RDS

I'm configuring newrelic for the first time and in order to configure rewrelic for my Postgres RDS instance, I was going through the instructions:

However, on my AWS console there's nothing as such Another AWS account role type:

I tried choosing rds-monitoring-role - but there I didn't get another further option for account ID etc.. Am I missing anything? Also, I'm on free AWS and newrelic account - can this be a problem as I'm seeing limited options?

Basically you need an IAM role with a policy including the permissions listed here:

• rds:ListTagsForResource
• rds:DescribeDBInstances
• rds:DescribeDBClusters

The Roles trust policy needs the following lines inserting:

• "Principal": {"AWS": "[ACCOUNT_ID]"},
• "Condition": {"StringEquals": {"sts:ExternalId": "[EXTERNAL_ID]"}}

Where [ACCOUNT_ID] and [EXTERNAL_ID] are replaced with the values above. This allows NR to assume this role to retreive your RDS instance metrics