Like the post says, you have to click on "Show more settings ..." in the template then change the value from "2456" to something like "2466", then delete the entry "UDP - Game Port Range" entirely, then click on "Add another Path, Port, Variable, Label or Device" from the drop down select "Port" at container port enter "2466-2468", at host port enter "2466-2468", at connection type select "UDP" from the drop down, click on "Add" and "Apply".
Now you have a server running on port 2466.
This is how the new entry should look like: