Alert plugin or Alert software to be integrated with Elastic stack in Basic License

We are using Elastic stack in Basic License , but we require alert configuration. If there is any, please respond. For version 7.5

The alert function of the stack elk is in the x-pack plugin which is not free

We don't speak about xpack plugin anymore as it's now packaged with the distribution.
But that's true that alerting is still a commercial feature available from gold level.
It's also included in the cloud.elastic.co offer if you're looking to host your cluster on internet.