Please add the following JS in your pages JS or site's JS You can use any plugin like insert header and footer code
<script type="text/javascript">
$(document).ready(function() {
// Add required attribute to installationDate field
$('input[name="installationDate"]').attr('required', 'required');
// Add required attribute to pr_reciepetAttachment field
$('input[name="pr_reciepetAttachment"]').attr('required', 'required');
});
</script>
This will do the trick! And make the Required fields both Attachments and The installation date.