How to test the JQL subtaskOf module on my Jira account

I am a junior react developer using forge on Jira and I am now just testing out the example projects that are provided on the Jira documentation. However, I find it difficult on how to run and test the function code that I wrote on my Jira account. I have finished deployment and installation to my Jira domain.

This is the Jira example apps that I am talking about

Thanks for giving attention to my bug. I am hoping to see any suggestion and advices.