How to upload files into SharePoint Online using Azure DevOps release pipeline?

Yes, you can upload your artifacts on sharepoint directory. Please find the Azure devops extension which will do the work.

https://marketplace.visualstudio.com/items?itemName=halliba.az-pipelines-2-sharepoint

This extension is well documented and all the necessary steps are given.

Thanks

You can use AzurePowerShell@5 Task to achieve this, More details here on this URL https://dev.to/kkazala/azure-devops-pipeline-with-workload-identity-federation-2gpj

Following is sample code

  - task: AzurePowerShell@5
    name: Upload Folder To SP
    inputs:
      azureSubscription: {SerivicePrincipal Name Created in ADO}
      azurePowerShellVersion: latestVersion
      ScriptType: InlineScript
      Inline: |

        try {
          $azAccessToken = Get-AzAccessToken -ResourceUrl "https://{tenantID}.sharepoint.com"
          $siteUrl = "https://{tenantID}.sharepoint.com/sites/{sitename}"
          $conn = Connect-PnPOnline -Url $siteUrl -AccessToken $azAccessToken.Token  -ReturnConnection
          Write-Host $conn.Url
        }
        catch {
            Write-Host "##[error] 1 (Connect-PnPOnline -AccessToken): $($_.Exception.Message)"
        }

        try {

          $lists = Get-PnPList -Connection $conn
          Write-Host "List names:"
          $lists | ForEach-Object { Write-Host $_.Title }
          
          $sharePointFolderUrl = "$siteUrl/Dokumente"

          Add-PnPFolder -Name $folderName -Folder $sharePointFolderUrl -Connection $conn


        }
        catch {
          Write-Host "##[error] 2 (Add-PnPFolder): $($_.Exception.Message)"
        }

Note: You have to use following command to provide permission for specific site

Grant-PnPAzureADAppSitePermission -AppId 'xxx'  -Site 'https://xx.sharepoint.com/sites/{sitename}' -Permissions Write

As an alternative, I described a solution using Power Automate to extract artifact from Azure Pipeline and upload to SharePoint: How to extract files from Azure Pipeline artifacts using Power Automate