How to add RDS Postgres in metabase

Hi, we are new in metabase and im doing the installation. I created a yaml template that i deploy in AWS Cloudformation, everything is working except i am unable to pass the existing RDS info to be used by the elasticbeanstalk for metabase database. Thanks.

Is that possible to put the value of the existing AWS RDS (postgres) using the “OptionSettings:” in the yaml template? Below is the value that im using but it just only put it on environment.

ConfigurationTemplates:
- TemplateName: MetabaseConfiguration
Description: Metabase Application Configuration
SolutionStackName: 64bit Amazon Linux 2018.03 v2.12.8 running Docker 18.06.1-ce
OptionSettings:
- Namespace: ‘aws:elasticbeanstalk:environment’
OptionName: EnvironmentType
Value: LoadBalanced
- Namespace: ‘aws:elasticbeanstalk:environment’
OptionName: LoadBalancerType
Value: application
- Namespace: ‘aws:elasticbeanstalk:environment’
OptionName: ServiceRole
Value: !Ref ElasticBeanstalkServiceRole
#RDS Options
- Namespace: ‘aws:elasticbeanstalk:application:environment’
OptionName: MB_DB_TYPE
Value: postgres
- Namespace: ‘aws:elasticbeanstalk:application:environment’
OptionName: MB_DB_DBNAME
Value: nameofdb
- Namespace: ‘aws:elasticbeanstalk:application:environment’
OptionName: MB_DB_PORT
Value: ‘5432’
- Namespace: ‘aws:elasticbeanstalk:application:environment’
OptionName: MB_DB_USER
Value: dbuser
- Namespace: ‘aws:elasticbeanstalk:application:environment’
OptionName: MB_DB_PASS
Value: password
- Namespace: ‘aws:elasticbeanstalk:application:environment’
OptionName: MB_DB_HOST
Value: localhost