You need to message someone either moderators or admin once your account has posted more than once or been around a couple of days.
I (with my moderator hat on) could deactivate your account, but it won’t go away completely: your posts with your username will remain - Discourse does this to preserve the threads of conversation. I think you have the option to later re-activate it if you wish providing you can re-verify your email.
We can also anonymize your account - basically it assigns you an “anon[bunch-of-numbers]” username. Once this is done you can’t get it back. Again your posts remain.
Admins may have more privileges, I don’t know as I am not one.
Okay, then. I’ll just leave for a long while, then. Probably won’t come back as a result. Just saying.
@dingotush is correct. The forum software we use has some restrictions to prevent data corruption but if you want to DM me I can work with you to see what we can do.
I’m thinking of doing the same thing, I have no use for my account anymore.