It is against Nabble's terms and conditions to do this on a free forum. I'm not clear how they monitor breaches but you risk your forum being taken down by Nabble if you do this.
If you pay for Premium Support (not a Premium Site, which only removes adverts) then you are allowed to. If you need instructions on how to do it, then a Post on Premium Support should get it done for you.
Volunteer Helper - but recommending that users move off the platform!
Once the admin for GregHelp now deleted.