Ajax loading for filter based on categories in Craft 3

Question

I have a page with blog listed with pagination using craft paginate.

{% paginate craft.entries.section(['blog']).orderBy('postDate desc').limit(15) as pageInfo, entryTemplates %}

Now I am need of filter with categories using ajax, so that on clicking the category, blogs based on the category will be listed.

I want to know how this happen with ajax. To where we will redirect the ajax request because we are not using any plugin.

 $.ajax({
            type: 'get',
            url: test/getFilteredData, // Where we will define this controller and action in craft 3
            data: {},
            processData: true,
            success: function(result){}
        })

so that from that url we will return the filtered data and displayed back. Thanks in advance.