Error creating event subscription

Hi, Here are a few things you can check and try to resolve the issue:

Topic ARN: 

Make sure that the ARN you're using for the SNS topic is correct. The error message indicates that the ARN arn:aws-us-gov:sns:us-gov-west-1:702344441970:RDS-DBNotifications.fifo is invalid. Double-check the ARN from the AWS Management Console or programmatically retrieve it to ensure accuracy.

Topic Name: 

Verify that the SNS topic name you're using exactly matches the one you've created. Case sensitivity matters in AWS resource names.

Permissions: 

Ensure that the IAM role or user you're using to create the event subscription has the necessary permissions to access the SNS topic. You can attach the AmazonSNSFullAccess policy to your IAM user or role temporarily for testing purposes.

Region: 

Confirm that you're creating the event subscription in the correct AWS region where the SNS topic exists (us-gov-west-1 in your case).

Topic Type: 

Check if the SNS topic is a FIFO (First-In-First-Out) topic. FIFO topics have specific requirements and limitations compared to standard topics. If you don't specifically need FIFO behavior, consider creating a standard SNS topic.

Retry: 

If all settings seem correct, try creating the event subscription again. Sometimes transient errors can occur.

If the issue persists after checking these points, you might want to provide more details about how you're creating the event subscription (e.g., through the AWS Management Console, CLI, or SDK) for further assistance. Additionally, reviewing CloudWatch logs or AWS CloudTrail logs can provide more insights into the specific error encountered during the creation process.