No subsecond precision for apache logs

Thank you for your time.
Sorry, I didn't explain myself better in the beginning. At the moment I get time normally like 'Aug 17, 2021 @ 01:19:03.000'.
I want to have it in subsecond. When I change logging in apache from seconds to milli or microseconds, elasticsearch creates new index for each log like 'apache-access-51627800.51'. My normal indices are created as 'apache-access-2021-33'(weekly indices).
I wanted to confirm if by changing mappings etc, i could achieve this(I have tried but in vain).
So now it's clear that I need to change it before ingestion to elasticsearch.