Import-Csv with a dialog box - powershell

Question

I am trying to add a dialog box into my Import-Csv script in Powershell v7. Basically, I do not want to remember different names of .csv files that have been exported from another script, so this will make it a lot easier. I have looked around and could not find anything that relates to what I am getting.
The code I have is this:
Write-Host "This will bulk add users to an AD group." -ForegroundColor Yellow
" "
# Import the data from CSV file and assign it to variable
[System.Reflection.Assembly]::LoadWithPartialName("System.windows.forms") | Out-Null
$OpenFIleDialog = New-Object System.Windows.Forms.OpenFileDialog
$OpenFileDialog.InitialDirectory = $InitialDirectory
$OpenFileDialog.Filter = "CSV (*.csv) | *.csv"
$OpenFileDialog.ShowDialog() | Out-Null
$Path = $OpenFileDialog.Filename
$Users = Import-Csv -Path $Path
# Specify target group where the users will be added to
# You can add the distinguishedName of the group. For example: CN=Pilot,OU=Groups,OU=Company,DC=exoip,DC=local
$Group = Read-Host "Enter in the target group name"
# Start transcript
Start-Transcript -Path "C:\Output Log\Users Logs\Add-ADUsers.log" -Append -UseMinimalHeader
foreach ($User in $Users) {
# Retrieve UPN
$UPN = $User.UserPrincipalName
# Retrieve UPN related SamAccountName
$ADUser = Get-ADUser -Filter "UserPrincipalName -eq '$UPN'" | Select-Object SamAccountName
# User from CSV not in AD
if ($null -eq $ADUser) {
Write-Host "$UPN does not exist in AD" -ForegroundColor Red
}
else {
# Retrieve AD user group membership
$ExistingGroups = Get-ADPrincipalGroupMembership $ADUser.SamAccountName | Select-Object Name
# User already member of group
if ($ExistingGroups.Name -eq $Group) {
Write-Host "$UPN already exists in $Group" -ForeGroundColor Yellow
}
else {
# Add user to group
Add-ADGroupMember -Identity $Group -Members $ADUser.SamAccountName
Write-Host "Added $UPN to $Group" -ForeGroundColor Green
}
}
}
Stop-Transcript
" "
Remove-Variable -Name Users
Write-Host "Users have finished adding to $group" -ForegroundColor Yellow
" "
}
The results of the output is this:
The search filter cannot be recognized
+ CategoryInfo : NotSpecified: (:) [Get-ADUser], ADException
+ FullyQualifiedErrorId : ActiveDirectoryServer:8254,Microsoft.ActiveDirectory.Management.Commands.GetADUser
+ PSComputerName : localhost
does not exist in AD
Note: "does not exist in AD" has a blank in front of it. I suspect it is because the import is not reading the file, but I cannot make sense of how to fix it.
Any help will be much appreciated!
Thank you in advanced.