Hello @Sing Kit Cheng,
As per description, we understand that you received email reminder asking to Upgrade to the latest version of Microsoft Entra Connect Sync by 30 April 2025 to avoid wizard impacts and you are working with Azure AD Connect v2.3.6.
The minimum supported versions are 2.4.18.0 for commercial cloud and 2.4.21.0 for non-commercial clouds, or any newer version.
You can download the latest version from the Microsoft Entra Admin Center under Manage.
Or, you can download the latest version of Microsoft Entra Connect 2.x from the below link.
https://www.microsoft.com/en-us/download/details.aspx?id=47594
As you are using older version of Azure AD Connect v2.3.6, we recommend you to upgrade to the latest version before 30 April, 2025.
Though the deadline has been extended, if you are not yet on a minimum supported version, you'll experience the following impacts after the original date:
After April 7, 2025, configuration of Active Directory Federation Services (ADFS) scenarios through Microsoft Entra Connect wizard won't work.
After April 7, 2025, configuration of PingFederate scenarios through the Microsoft Entra Connect wizard won't work.
After April 30, 2025, all authentication requests to Microsoft Entra ID on the Microsoft Entra Connect wizard will fail. Some of the capabilities that will be impacted include schema refresh, configuration of staging mode and user sign-in changes.
For example, when calling the MSOnline PowerShell cmdlet Get-MsolUserRole, Microsoft Entra Connect wizard throws an error: "Access Denied. You do not have permissions to call this cmdlet"
But, you will be able to perform the below things.
Your sync service will run as usual, and changes will continue to sync to Entra
The ability to upgrade your Entra Connect Sync instance. You can still perform the upgrade after April 30, 2025
There are a few different strategies that you can use to upgrade Microsoft Entra Connect.
Permissions required to upgrade
When you upgrade from one version of Microsoft Entra Connect to a new release, you need the following permissions:
You can follow the below document to upgrade Entra Connect to the latest version.
https://learn.microsoft.com/en-us/entra/identity/hybrid/connect/how-to-upgrade-previous-version
I hope this information is helpful. Please feel free to reach out if you have any further questions. If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".