You can reward a Helper with a bit of additional money if they complete a task well.

To simplify this process, we built the tipping function inside our platform. Therefore, this option will be visible when you release the payment to the Tasker.

When you select Release Payment, the various tipping option will be displayed to you. However, you may only add tips in predetermined amounts, and the overall task value must still not exceed our maximum of €9,999.

It's fine if you decide not to provide a tip as well. Simply pick the pre-selected option of "I'd rather not" and proceed to release payment on the site.
Remember that a service fee is deducted from every payment made through Taskhelper; this includes tips.