I am in trouble, I made a test subscriptions group in iTunes connect, but now I cannot delete it. Is there any way to delete it?
You should be able to delete a Subscription Group, if there are no subscriptions in it.
If you have subscriptions within the Subscription Group, start by deleting the subscriptions first. You can find the Delete This Subscription text-button at the bottom of the subscription detail page.
When your Subscription Group is empty, a Delete This Subscription text-button would appear at the bottom of the Subscription Group's detail page. Clicking that should do the job. 👌🏽