Find Unity editor installations from Unity Hub

Get-UnityInstallationRoot.ps1

function Get-UnityInstallationRoot {
    $userPathFile = "$env:APPDATA\UnityHub\secondaryInstallPath.json"

    # Check if Unity Hub is installed, if installed, then must come with this file
    if (-not (Test-Path $userPathFile)) {
        Write-Warning "Unity Hub not installed."
        return $null
    }

    # By default, it only has two quotes: ""
    # So $userPath will be empty string by default
    $userPath = (Get-Content $userPathFile -Raw).Trim('"')

    # If userPath directory is set but deleted.
    # Unity Hub will recreate directory upon next Editor installation.
    if ((Test-Path $userPath)) {
        return $userPath
    }

    # Default path
    $defaultPath = "$env:ProgramFiles\Unity\Hub\Editor"

    if (Test-Path $defaultPath) {
        return $defaultPath
    }

    Write-Warning "Could not determine Unity Editor installation path."
    return $null
}

Get-UnityInstallationRoot | Get-ChildItem | Select-Object FullName

The %APPDATA%/UnityHub/secondaryInstallPath.json should be "" by default unless user override the setting👇