How to run a delta/initial sync using PowerShell

In order to run a sync, you need to be on a computer where Microsoft Azure Active Directory Connect is installed. Please follow the steps mentioned below to run a delta/initial sync using PowerShell:

1. Run PowerShell as an administrator.
2. Import the required module to run a sync

Import-Module ADSync

      3. Now run the following command to initialize the AzureAD Sync immediately.

Start-ADSyncSyncCycle -PolicyType Delta

Note: This will only sync current changes.  Run the following command to force a complete sync but note that the length of sync time would be greatly increased.

Start-ADSyncSyncCycle -PolicyType Initial

Please refer to the link mentioned below for further details:

https://techcommunity.microsoft.com/t5/itops-talk-blog/powershell-basics-how-to-force-azuread-connect-to-sync/ba-p/887043