amplify api add-graphql-datasource is returning error

Hi, I am trying to connect Aurora Postgres with amplify, I created DB and when I run command: amplify api add-graphql-datasource it returns this error:

🛑 There was an error adding the datasource
🛑 User: arn:aws:sts::xxx:assumed-role/us-east-1_ocb0gotWz_Full-access/amplifyadmin is not authorized to perform: rds:DescribeDBClusters on resource: arn:aws:rds:us-east-1:xxx:cluster:* because no identity-based policy allows the rds:DescribeDBClusters action

I am an admin user and have full access to all resources. a step-by-step instruction to resolve this would be greatly appreciated. Thank you