We installed this app on the search head, but we do not see all the indexes from the indexers.
1 search head, 3 indexers clustered.
Any thing which need to install on the indexers?
Did you confirm your search factor and replication factor is met and that the indexes match the settings for other working indexes?
Additionally, if indexes don't have data in them, you won't see them. You can try oneshot add of data to that index and see if it appears.