How do I access SharePoint with PowerShell 7?

Hello everyone,

I'm trying to create a PS script that reads the set permissions of a folder from SharePoint and creates a copy of it with the same rights.

In MS Entra Admin Center, I've created a new app and granted it numerous permissions for testing purposes.

My PS7 script looks like this:

$clientId = "[...]"
$clientSecret = "[...]"#Value, not the ID 
$tenantId = "[...]" 
$siteUrl = "[...].sharepoint.com/sites/ExterneKundendaten" 
$libraryName = "Dokumente" 
$folderPath = "_Unsortiert" 
try { 
$connection = Connect-PnPOnline -Url $siteUrl -ClientId $clientId -ClientSecret $clientSecret Write-Host "Connection successfully established" 
} 
catch { Write-Host "Connection error: $_"}

I'm getting the following error message:

Connection error: The remote server returned an error: (401) Unauthorized.

For testing, I've also tried the following connection setup:

$clientSecretSecure = ConvertTo-SecureString $clientSecret -AsPlainText -Force
Connect-PnPOnline -Url $siteUrl -ClientId $clientId -ClientSecret $clientSecretSecure

Connect-PnPOnline -Url $siteUrl -ClientId $clientId -ClientSecret $clientSecret 
Connect-PnPOnline -Url $siteUrl -ClientId $clientId -ClientSecret $clientSecret -Tenant $tenantId 

$clientSecretSecure = ConvertTo-SecureString $clientSecret -AsPlainText -Force 
Connect-PnPOnline -Url $siteUrl -ClientId $clientId -ClientSecret $clientSecretSecure -Tenant $tenantId 

Unfortunately, all without success.

This is roughly how the later process should be, but it's already stuck at point 1

1. Establish connection to SharePoint Online
2. Define library name and folder path
$libraryName = "Dokumente" # Name of the document library 
$folderPath = "_Unsortiert" # Path to the folder 
3. Get the list item for the folder
$folderItem = Get-PnPListItem -List $libraryName -FolderServerRelativeUrl "/sites/ExterneKundendaten/$libraryName/$folderPath" 
4. Get the role assignments for the folder
$roleAssignments = Get-PnPRoleAssignment -List $libraryName -Identity $folderItem.Id 
5. Display permissions
$roleAssignments | Format-Table Principal, RoleDefinitionBindings 
6. Disconnect
Disconnect-PnPOnline 

PSVersion 7.4.6

PnP.PowerShell 2.12.0

Does anyone have an approach on how I can proceed and/or can someone recommend a good (and current!!) tutorial?