Extra Fees are not mandatory. But if you have extra fees and taxes you should add them separately. Most channels wish to display all fees separately to the guest to avoid confusion of what is included. There are also legal requirements in some countries that tax is kept separate from the rental price.
For this reason, we recommend that you add extra fees and taxes separately, so you can be accepted by all channels.
Extra Fees can be added on the Edit Property menu (Step 5 - Price & Availability).