How to increase replicas for .kibana_1 index

Hi Team,

I am having a cluster having 4 data nodes and two coordinator nodes with 3 masters.

I found that by default every new index created with 1 shard and 1 replica and I also changed default settings with 2 primary and 2 replica successfully for every new indices.

However, my I found that I’ve already ended up with already got created .kibana_1 index with 1 shard and 1 replica.

Issue definition: I am not able to increase its replicas while increasing its replicas to 3 even through already acknowledged through API.

Any help here will be much appreciated.