Getting HTML and Javascript into entity framework database

I store some data in textboxes how do I get this into the entity framework database?

<h1>Hello, world!</h1>
<h2>The time on the server is @DateTime.Now   </h2>
<input id="lat" name="lat" type="text" value="" />
<input id="long" name="long" type="text" value="" />
<script>

    const searchParams = new URLSearchParams(window.location.search);
    var lat = searchParams.get('lat');
    var long = searchParams.get('long');
    alert("LAT:" + lat + " LONG:" + long);
    var lato = document.getElementById('lat');
    var longo = document.getElementById('long');
    lato.value = lat;
    longo.value = long;

</script>