How to connect to a postgreSQL instance on AWS RDS

Hi, EylesIT 

According to your description, you are trying to connect to postgreSQL using Power BI, but it has not been successful, you need to confirm that:

1.Whether NpgSQL is the latest version, and whether the GAC option is enabled during installation.

2.configure security groups: you may need to create a security group in AWS's VPC to allow internet access to the database port (default value is 5432).

You can try to use the Postgres connector to fetch data from the data source you deployed on AWS. You will then need to use the gateway to manage the data source refresh (turn on the option to use the gateway to handle cloud data sources) and install Remote Access Credentials (which is used to authenticate with AWS credentials) on the device where you installed the gateway and handled these operations.

Related Link: Merge or append on-premises and cloud data sources 

BTW, you can take refer to the following blog if it helps:

Connection of Power BI with RDS PostgreSQL on AWS from Scratch 

Best Regards,
Yang
Community Support Team

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If I misunderstand your needs or you still have problems on it, please feel free to let us know. Thanks a lot!

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