Is it possible to change the username or delete the account in this forum? I have replied to the initial pm but got no response, and I can’t pm anybody else since I have to low trust level…
No, you should just create a new account.
I just want to anonymize my username, an admin can do it I think. I have had it done before on a site using the same forum platform. https://github.com/discourse/discourse. Sure it is not possible?
I’m an admin, pm me!
I would, but I can’t 
I have not enough reputation. Would you mind PM:ing me?