Go to your LaunchPass dashboard and click "Paid Group".
Set the name of the channel. Setting the channel name will create both a role and channel within Discord with the same name. If you use the exact name of a channel or role already within your server, the system will connect to those roles/channels. The names have to be identical, lowercase and no spaces or symbols for it to find them.
Configure the role created within the server any way you want.
When members purchase access and they are new to the server the role will be immediately applied. If they already had access to the server, they will get the role after sending the activation code found on their welcome email to the LaunchPass Bot.