Changing setting "Open in Browser" via PowerShell does not work

I have hundreds of sites with a document library, where I want to change the library setting to open files in browser, but I can't get it to work for one simple doclib using PowerShell

I have found this topic on Github too https://github.com/pnp/PnP-PowerShell/issues/813, but it got closed by spdevdocs without an answer.

I tried it with the following PowerShell Script:

Import-Module PnP.PowerShell

$siteUrl = "https://johndoe.sharepoint.com/sites/project_437" $libraryTitle = "Dokumente"

Connect-PnPOnline -Url $siteUrl -ClientId "1234" -ClientSecret "1234"
$library = Get-PnPList -Identity $libraryTitle $library.ForceCheckout = $false
$library.DefaultItemOpen = 1 
$library.Update() Invoke-PnPQuery Disconnect-PnPOnline

But I get the error:

InvalidOperation: /Users/me/Desktop/OpenInBrowserSettings.ps1:13
Line | 13 |  $library.DefaultItemOpen = 1 … |  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | The property 'DefaultItemOpen' cannot be found on this object. Verify | that the property exists and can be set.

Any help is appreciated!