Hi Deriv Community Members,
You may withdraw the free bonus amount once you have exceeded an account turnover of 25 times the bonus amount value.
This is explained in our Terms & Conditions in detail: https://deriv.com/tnc/funds-and-transfers.pdf
You may also find this on our website; https://deriv.com/ > bottom of the page, Legal (Terms and conditions) > Funds & transfers
We hope this will help you with your doubts and for further assistance, you may contact us via LiveChat