Sharepoint online powershell usercustomactions scriptblock not working

Question

I want to add a warning message at the top of the SP online site. For that i tried UserCustomActions using powershell, code is running without error but not working. I tried to add ribbon control that is working. I have enabled the allow script option in the admin site. Below i included the code for reference.

[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SharePoint.Client")
[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SharePoint.Client.Runtime")

Function Add-ScriptLinkAction([Microsoft.SharePoint.Client.ClientContext]$Context,[String]$ScriptBlock,[int]$Sequence)
{

    $action = $Context.Site.UserCustomActions.Add();
    $action.Location = "ScriptLink"
    <#
    if($ScriptSrc) {
        $action.ScriptSrc = $ScriptSrc
    }#>
    
    if($ScriptBlock) {
        $action.ScriptBlock = $ScriptBlock
    }
    $action.Sequence = $Sequence
    $action.Name = "title"
    $action.Title = "title"
    $action.Update()
    $Context.ExecuteQuery()
}

$siteUrl = 'https://stginfotechchennai.sharepoint.com/sites/ProductQualityReseachCenter'
$context = New-Object Microsoft.SharePoint.Client.ClientContext($siteUrl)
# SPO credentials
$context.Credentials = Get-SPOCredentials -UserName [email protected]

Add-ScriptLinkAction -Context $context -ScriptBlock $ScriptBlock -Sequence 1000 

Answer 1

For modern page,we need to use spfx extension to add js file to page.If your code is ok,classic page should work well.