Here's how you can set a Limit Order:
1. Go to the asset page of any coin for which you want to place a limit order.
2. Click on the 'Buy' button.
3. You will see the current market trend. In the top right, you can see an order type. This is your current order type.
4. If you tap on the order type, you can select 'Limit Order' from the list.
5. Click on 'Preview Buy'.
You should receive a success message for your Limit Order on the app itself.