sum in footer of datatable using ajax

Hello Sir/Mam,
currently, I work in asp.net core 2.2.
I can display data using ajax
here are the code and image

<script>
    $(document).ready(function () {
        $('#example').DataTable({
            "processing": true, // for show progress bar
            "filter": true, // this is for disable filter (search box)
            "ajax": {
                "url": "../api/InvestigationAPI/indexx",
                "dataSrc": ""
            },
            "columns": [
                { "data": "investigation", "autoWidth": true },
                { "data": "price", "autoWidth": true },
                { "data": "price", "autoWidth": true},
            ],
    
        });

    });

data display successfully. But here problem that how to display the sum of price column in the footer and in the total payable textbox
and how can I export data from this table I try many methods which mention here and also google

sorry for my English

thanks
</script>

Edited by Kevin:  Syntax highlighting. Details on how to highlight code using markdown can be found in this guide