How can I remotely delete a file in document library in sharepoint online using remote event receiver?

If you want to trigger file delete event, we need use remote event receiver with CSOM to achieve it. If you only want to delete a file in SharePoint Online document library in client side, we can use PowerShell with CSOM or PnP PowerShell to achieve it.

#Load SharePoint CSOM Assemblies Add-Type -Path "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\16\ISAPI\Microsoft.SharePoint.Client.dll" Add-Type -Path "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\16\ISAPI\Microsoft.SharePoint.Client.Runtime.dll" Function Remove-SPOFile() { param ( [Parameter(Mandatory=$true)] [string] $SiteURL, [Parameter(Mandatory=$true)] [string] $FileRelativeURL ) Try { #Get Credentials to connect $Cred= Get-Credential $Credentials = New-Object Microsoft.SharePoint.Client.SharePointOnlineCredentials($Cred.Username, $Cred.Password) #Setup the context $Ctx = New-Object Microsoft.SharePoint.Client.ClientContext($SiteURL) $Ctx.Credentials = $Credentials #Get the file to delete $File = $Ctx.Web.GetFileByServerRelativeUrl($FileRelativeURL) $Ctx.Load($File) $Ctx.ExecuteQuery() #Delete the file $File.DeleteObject() $Ctx.ExecuteQuery() write-host -f Green "File has been deleted successfully!" } Catch { write-host -f Red "Error deleting file !" $_.Exception.Message } } #Set parameter values $SiteURL="https://tenant.sharepoint.com/sites/lz/" $FileRelativeURL="/sites/lz/Shared Documents/test.pptx" #Call the function Remove-SPOFile -SiteURL $SiteURL -FileRelativeURL $FileRelativeURL 

PnP PowerShell:

#Config Variables $SiteURL="https://tenant.sharepoint.com/sites/lz/" $FileRelativeURL="/sites/lz/Shared Documents/test.pptx" #Get Credentials to connect $Cred = Get-Credential Try { #Connect to PNP Online Connect-PnPOnline -Url $SiteURL -Credentials $Cred #Try to Get File $File = Get-PnPFile -Url $FileRelativeURL -ErrorAction SilentlyContinue If($File) { #Delete the File Remove-PnPFile -ServerRelativeUrl $FileRelativeURL -Force Write-Host -f Green "File $FileRelativeURL deleted successfully!" } Else { Write-Host -f Yellow "Could not Find File at $FileRelativeURL" } } catch { write-host "Error: $($_.Exception.Message)" -foregroundcolor Red }