slack invite link in OP doesn't work; someone has another invite link?
We had a problem with a spammer in the slack, we had to disable all slack invite links because of this. We activated the slack links a few days later but he kept coming back with new accounts... If you would like to be added, send me a PM with your e-mail address and i'll add you to the slack.
I just suggest moving to Discord the entire slack. Its easy to manage spammers on discord, you can prevent access to trolls except those who verify themselves.