How to update the label description for a particular language using X++ code in D365 FO

Can anyone help me on updating the label description for a particular language in D365 FO

What exactly do you mean by that?

Want to upload arabic description for my custom label ids

You can’t do that in X++. Add labels in Visual Studio, commit them to version control, let your build server create a deployable package and install this package to F&O enviroments.