Once approved as a verified Trade Vendor, you can go to the Vendor Area of your Coindirect account and select ‘Post an Offer’.
From there, you can choose whether you want to create a 'Buy' or 'Sell' offer and follow the instructions accordingly.
In order to start getting Orders, make sure that you've setup a Payment Method in your Coindirect Personal Details profile and that you've deposited or bought digital currency to topup your Coindirect wallet balance.
Update (12/07/2018): You can now buy and sell not only Bitcoin, but also Bitcoin Cash, Dash, Ethereum, Litecoin, USDT and Ripple.