How to correct custom logstash index name for use by ILM

Sorry, here is the other thread that details my problem exactly, with a hint at a solution but I unfortunately needed more details concerning fixing the index name:

Here is my error:

illegal_argument_exception: index.lifecycle.rollover_alias [filebeat-7.8.0] does not point to index [asa-2020.08.18]

My simple policy is this:

PUT _ilm/policy/Delete-After-7 { "policy": { "phases": { "hot": { "min_age": "0ms", "actions": {} }, "delete": { "min_age": "7d", "actions": { "delete": {} } } } } }

Not sure how to format about code, the back tic is not working for me. Apologies.

Also not sure how to post template as there is tons of information, however it is the default Filbeat 7.8 template with the only change that I applied the template to also include "asa-*" which is not functioning as far as ILM