Under the "Network" tab find the button labeled "CREATE ALLOCATION" as shown below
If you cannot see this open a ticket
Next, you will see a new port allocated to your server, you will grab the one that does not have the label "Primary" as that is your primary server port so leave that alone and the port you wanna grab will look like something below
DO NOT MAKE IT PRIMARY AND DO NOT USE THE PRIMARY ONE
Then head over to the "Startup" tab and you will toggle txAdmin to on and change the txAdmin port to what you grabbed from the previous page It will look something as shown below
To access your txAdmin panel you will type in your browser yourserverIP:txAdminport or it will be shown as well on startup in the console as shown below