First, head over to the settings of the product you want to edit and choose the Pricing tab. If you don't have defined your default prices, in this article we explain how to create pricing tables from scratch.
In the image below, you can see the different alternatives you can choose to have for channel specific pricing. In this example, let's observe the two top rows.
If you want to offer cheaper price for 1 day rentals for customers who make their reservation online, you have to create two price variants for the one day rental. For the first one, select the in-store channels (admin, self-service) and fill out the price. For the second one, select online from the drop-down menu, and fill out the discounted price based on your company's pricing policy.
That's it. With the same logic, create channel specific prices for all the pricing variants that you want. You can also hide different durations from different channels, for example, if you want to avoid getting under one-day reservations through your online shop.