There are three ways to enter tips at the cash register.

Integrated terminal
If you have an integrated terminal, you charge as usual.

As long as tips are enabled on the terminal, the customer will be asked to enter the total amount they wish to pay. The amount that exceeds the total amount will be registered as a tip.

Through Tip button
If you want to register tips outside of a sale, you can add a Tip button on the right side of the cash register.

When you press this button, you will be taken to the Tip overview where you can see previously registered Tips.

Press "Register tip" if you are going to register a tip.

You will then see a new window where you can enter the Tip amount and select the desired payment method.

Register bill as tip
When the customer pays more than the total amount in cash, you will be given the choice between returning the extra amount in bill or registering it as a tip.