For whose of you stuck with the HA Companion app not working due old Webview, on an Android panel with ARM processor and without the Google GMS suite…
This is how I solved the update of the webview on this IIyama (took me days to figure this out).
Get an USBstick or microSD card, format it FAT32, and download the following apps on the stick first via your PC/Mac:
Android Webview:
https://www.apkmirror.com/?post_type=app_release&searchtype=apk&s=Android+System+WebView
or from here:
FlashFire:
Xposed installer:
Xposed SDK27 script.zip for ARM processor:
https://web.archive.org/web/20210507000410/https://dl-xda.xposed.info/framework/sdk27/
Anywebview:
Home Assistant companion minimal version:
https://github.com/home-assistant/android/releases/download/2023.7.5/app-minimal-release.apk
THEN:
Reboot the IIyama ProLite. (maybe do a factory reset first, so nothing is in the way).
Enable the android developer mode. If you don’t know how, Google something like “enable developer mode android oreo”. It’s easy and you need it later to set the actual Webview to the new one.
Then put the USBstick in it. Open the App installer to install the apps in the sequence as below:
Install the Xposed app installer, from your USB stick.
After opening it will say it’s not completely running, that is correct.
Install FlashFire, from your USB stick. And then start the app and + upload the zip script and flash.
How? Do what they say in this instruction movie, scroll to 2min45 to the point were he starts the app: https://www.youtube.com/watch?v=bVXP_ZfJCL0
When you upload Xposed Zip script you do the flash and reboot.
When it’s all done the Xposed app wil now be green and running.
Install Anywebview, from your USB stick
Go to the Xposed app and enable the “any webview module”.
You need to reboot to make it effective.
Install the Android System Webview, from your USB stick.
Now reboot.
When back, go to the developer settings. And there choose the new Webview.
Install the Home Assistant minimal, from you USB stick.
Enjoy!
When it worked, i’ve uninstalled these FlashFire and Xposed, and the new webview kept working without them.
I got some original info from here: Update WebView on NSPanel Pro and Tuya Smart Home Panels | Blakadder's Smarthome Shenanigans
But it’s not completely useable for the Prolite panel because it’s an ARM processor, and not ARM64, also the Prolite panel refuses ADB via connections ethernet what ever I tried.
I think this will work for most cases since all these iiyama panels are probably the same,
If everything fails: I don’t know what to do, i’m not an expert, do a factory reset 
