In MVC5 there is @Ajax.ActionLink
that is useful to update just a partial view instead of reloading the whole View. Apparently in MVC6 is not supported anymore.
I add ajax options for Anchor TagHelper in ASP.NET MVC Core
you can see complete sample in github link : https://github.com/NevitFeridi/AJAX-TagHelper-For-ASP.NET-Core-MVC
after using this new tagHelper you can use ajax option in anchor very easy as shown below:
Add Menu