How to replace subscribe() in RBatchReactive.execute().subscribe()

Given below is a piece of Java Micronaut code I am using for removing entries from redis. But this code does not remove entries from redis. If I use batch.execute().subscribe(); then it is working, but I do not want to use subcribe(), so is there any solution for that?

private Mono<Void> removeFromRedis(String[] entries) {    var batch = redis.createBatch();    batch.getMap("map_name").fastRemove(entries);    batch.execute(); //if I use batch.execute().subscribe(); here then it will work    return Mono.empty();}