Retention policy for Transform's index

Hi,

If I set a retention policy on a Transform, like 7 days, the whole index will be deleted after 7 days.

How can I set up something like "delete the data older than 7 days, and keep the rest alive"?

Thanks!

image

At the end of point 4 right here:

https://www.elastic.co/guide/en/elasticsearch/reference/current/ecommerce-transforms.html#ecommerce-transforms