Connecting my nbn

Level 1c
On the website it had an important note and it said:
Important! Do not use a line filter/splitter (from your old ADSL service) when plugging in the Network Connection Device.  my question is what other outlet do i use or what else should I do to fix this problem...
Level 8

Your NBN connection box (if FTTC) or the wifi router (if FTTN) will plug directly into the wall socket. Or you might need an adaptor plug to go from the small RJ11 plug into the old style 3-pin wall socket.

If you have any other phone outlets in your house, you can't use a phone in them.