7zip - Vergebenes Passwort wird nicht uebergeben

# Define folders
$7zipPath = "$env:ProgramFiles\7-Zip\7z.exe"  
$SourceFolder = "C:\Group Drives\ABC\XYZ\"  
$DestFolder = "C:\Staging\A\"  
$FileName = "A_Backup_" + (Get-Date –format "yyyyMMdd_HHmmss") + ".7z"  
$Archive = $Destfolder+$FileName
$FinalDestFolder = "Y:\Backups\A\"  
$FileEnding = "*.7z"  

Set-Alias 7z $7zipPath

# Build archive for today
7z a -t7z -mmt=8 -mx=9 -mfb=64 -md=32m -ms=on $Archive $SourceFolder

# Move archived file to backup destination
Move-Item -Path $Archive -Destination $FinalDestFolder 

# Delete old files 
$n  =5
$items = Get-ChildItem "Y:\Backups\A\*.7z"  
$items | 
  Sort-Object Name -Descending | 
  Select-Object -Last ($items.count - $n) | 
  Foreach-Object { Remove-Item $_ }

Read-Host "AbCdEfG1357924680" -AsSecureString | ConvertFrom-SecureString | Out-File "C:\Backup\passkey.txt  

 ConvertTo-SecureString "AbCdEfG1357924680" -AsPlainText -Force | ConvertFrom-SecureString | Set-Content "C:\Backup\passkey.txt"  

$pass = Get-Content "C:\Backup\passkey.txt" | ConvertTo-SecureString  

7z a -t7z -p$pass -mmt=8 -mx=9 -mfb=64 -md=32m -ms=on $Archive $SourceFolder