Click on your profile Icon (It's on the top-right corner of the screen)
Click on "Request Payout"
Click on "Withdraw Money" and enter your account details - Don't forget to include the Bank's name.
If you get a notification saying: You can only withdraw funds if your current Balance and funds available for withdrawal are above ₦10,000.00 then it means you have to have at least N10,000 before withdrawing your funds in the first place.
OkadaBooks' minimum payout is 10,000 naira.
This is to avoid excessive bank charges.
If you are outside Nigeria, you'll get your funds through PayPal.