If you have made one or less posts and your account is new, you should be able to go to the account settings and delete it yourself.
Beyond that, the assumption the software makes is that you have contributed in some meaningful way that would be very disruptive to the flow of conversation if all your posts just disappeared. In that sense, deletion would not be appropriate. In this event, you would need to contact staff to have your account anonymized. This is a GDPR-friendly solution that removes all identifying information (i.e. your data) from the account and changes your username to something random like user321487686. Your posts will remain, but only that.