Put Fix-WeaponZenoFOV.ps1 in your steam game folder. (ala C:\Program Files (x86)\Steam\steamapps\common\ZenoClash)
Load a powershell window there and run it. If you've never run a powershell script before you'll probably have to google how to get arounds Microsoft's default no-script policy. Or maybe ask AI to convert this to batch script.
Run:
./Fix-WeaponZenoFOV.ps1
It'll ask what FOV you want for normal, and zoom. Or press enter to use the defaults of 100 FOV normal, and 90 for "zoom".
PS C:\Program Files (x86)\Steam\steamapps\common\zenoclash> .\Fix-WeaponZenoFOV.ps1
Default FOV : 90
Default zoom_FOV: 80
Enter desired FOV (or press Enter for 90):
Enter desired zoom_FOV (or press Enter for 80):