<form name="nameFORM" action="/heheh.php" method="post">
<input type="hidden" name="BeforeBase" value="data">
<input type="hidden" name="base" value="valuedata">
</form>
<a href="#" onclick="submitBTN()" class="shadow-lg w-50 btn fw-bold border ">
<script>
function submitBTN() {
document.nameFORM.submit();
}
</script>