JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" id="kennzeichen" name="kennzeichen" placeholder="ABC-DE ">
<br />    
<span id="koordianten"></span>

JavaScript

function error() {
    alert("Fehler");
}

function savePosition(position) {
    var kennzeichen = $("#kennzeichen").val();
    if(kennzeichen){  
        $.ajax({
            type: "POST",
            url: "/echo/json/",
            data: {lat: position.coords.latitude, lng: position.coords.longitude, kennzeichen: kennzeichen},
            complete: function(){
                $("#koordianten").append("Punkt 1: "+position.coords.latitude+" | Punkt 2: "+position.coords.longitude+"<br />");
            }
        });
    }
}

navigator.geolocation.watchPosition(savePosition,error,{ frequency: 1000 });