Or
1.
procedure TMainForm.UniButton1Click(Sender: TObject);
begin
UniHTMLFrame1.HTML.Add('TEST<br>');
//UniHTMLFrame1.JSInterface.JSCallDefer('body.scroll', ['b', UniHTMLFrame1.JSInterface.JSStatement('Infinity')], 100);
end;
2. UniHTMLFrame1 -> ClientEvents -> ExtEvents ->
function afterupdatehtml(sender, eOpts)
{
sender.body.scroll('b', Infinity);
}