Unity with SignalR

Hi guys, I'm having trouble to use signalr in unity. I downloaded the signalr package from nuget and put it in Plugins folder. It throw me error "unity error cs1703: an assembly 'newtonsoft.json' with the same identity has already been imported. consider removing one of the references" How do I solve this issue? Hopefully someone can point me to right direction. I'm using Unity 2107.1 and trying to use signalr.client v2.2.2 Thanks