Even if you’re completely new to Unity, you can download it and wrap a 360 THETA video onto a sphere. Unity Personal Edition is free.
There’s a writeup here:
and video with no sound. The video is intended to support the blog.
Here is the Unity Package file
This is for video files, not live streaming.
If you’re interested in streaming, check out
Using RICOH THETA Live view with Unity wired connection
WiFi Streaming THETA S in Unity untethered, low resolution and low framerate. Mainly for hobbyist or experimentation.