unable to export rds db snapshot to S3

I understand you're having trouble exporting an RDS DB snapshot to S3, with the export option being greyed out. There are several reasons why this might be happening:

1. DB Engine Compatibility: Not all RDS database engines support exporting snapshots to S3. Specifically, RDS for Db2, RDS for Oracle, and RDS for SQL Server do not support this feature. If your snapshot is from one of these engines, you won't be able to export it to S3.

2. DB Engine Version: Even for supported engines, not all versions may allow S3 exports. Make sure you're using a version of the database engine that supports this feature.

3. AWS Region: The S3 export feature might not be available in all AWS regions. Ensure that your RDS instance is in a region that supports exporting snapshots to S3.

4. Snapshot Type: While you can generally export all types of DB snapshots (including manual, automated, and AWS Backup service snapshots), there might be specific limitations based on how the snapshot was created.

To troubleshoot this issue:

1. Verify the database engine and version of your RDS instance.
2. Check if your AWS region supports exporting snapshots to S3 for your specific database engine and version.
3. Ensure that your IAM user or role has the necessary permissions to perform the export operation.
4. If you're using RDS for PostgreSQL, you can verify S3 export support for your version using the AWS CLI command: aws rds describe-db-engine-versions --region [your-region] --engine postgres --engine-version [your-version] | grep s3Export

If the export option is still greyed out after checking these points, you may need to contact AWS support for further assistance, as there might be account-specific issues or limitations.
Sources
Exporting DB snapshot data to Amazon S3 for Amazon RDS - Amazon Relational Database Service
Supported Regions and DB engines for exporting snapshots to S3 in Amazon RDS - Amazon Relational Database Service
Exporting data from an RDS for PostgreSQL DB instance to Amazon S3 - Amazon Relational Database Service

The Export to Amazon S3 console option appears only for snapshots that can be exported to Amazon S3. A snapshot might not be available for export because of the following reasons:

The DB engine isn't supported for S3 export.

The DB engine version isn't supported for S3 export.

S3 export isn't supported in the AWS Region where the snapshot was created.