The ip should be 127.0.0.1, The port should be the post the API is set to in VTS. If you dont have touch portal pro you can not use plugins so make sure you have that (Nothing I can do about this sorry). If you do have TP pro then load things in this order, VTS > TP on phone > TP on PC.
Just tested on v3.1 build 2 and seems to be working fine for me. If this is the first time you are trying to use it please try updating Java. If you were using it before please contact me on Discord and I will try and work out what the issue is for you there.