The organization administrators or members can delete a topic created by the test and the topic that you created incorrectly.
Step by step on deleting a topic:
1. Open the menu on the topic header by clicking the “...” icon located on the top right-hand corner.
2. Click "Delete this topic permanently" on the setting page
3. Before clicking yes, please make sure that it is the topic you want to delete as all messages within the topic will be permanently deleted.
If you just want to hide the topic from the topic list and you want to keep the topic as a log, you can use the archive topic feature. See more details.