It seems under current procedure, since you have one number assignment.
You will need to convert your existing node to NNX,
which basically converts that one node number to 10 node numbers by adding a digit to the tail end.
So, you will want to convert the existing node to NNX and then you will have 9 others to assign.
63118 would become 631180 or what ever last digit you assign. https://wiki.allstarlink.org/wiki/NNX