Using Pixel Streaming VR in PICO

Hello everyone, I am currently using the experimental feature VR of Pixel streaming. I successfully opened the page in the VR device and entered the VR scene through webXR following the instructions in the documentation. Although the head-mounted display is functioning properly, the input buttons on the controller do not work. Nevertheless, I can still detect the movement of the controller. How can I solve this issue? I am using the engine version 5.6(only the source code compiled for the win64 platform) and the corresponding version of Pixel streaming infrastructure. My VR device is PICO UE4.

Additionally, I also attempted to install the plugins provided by PICO and modified the input mapping, but it still didn’t work.

I am also using VR Pixel Streaming on device PICO, the documentation says that press the XR button to change into VR(The example device is Meta Quest), but my PICO do not work, it will navigate to a page informing me to scan some type of QR Code, and a alert saying that my device is not supported with Google Play service, can’t run edge, there is a skip button on the right of bottom, I clicked and then it turn to a some kind of fallback VR mode in which there is still two same viewport, I am still in browse not in the VR scene itself.
How did you entered the VR scene throug webXR?
My device is Pico4 Pro