Telegraf cloudwatch input rds metric

Hi i’m using telegraf with cloudwatch input.
i tried to collect RDS metrics, but some of the metric is missing.

https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/Aurora.Monitoring.html

As you can see at the URL above,
[VolumeBytesUsed, VolumeReadIOPs, VolumeWriteIOPs] exist, but telegraf can’t collect them.

Can you fix it for me?
.