2FA is an extra layer of security designed to keep your account, and your funds safe. When 2FA is enabled, it essentially means that every time your account is logged into using your email and password, a unique one time code that is regenerated every 30 seconds on your personal device is also required to complete sign in.
This is designed to mitigate the risk of anyone but you using your credentials to log into your account - we highly recommend setting 2FA up as soon as you set your Netcoins account prior to sending any funds to maximize safety.
For security and regulatory reasons, 2FA is a mandatory requirement in order to withdraw funds from your account and there is no way to withdraw coins from your without it enabled. If you do not have 2FA enabled on your account, the system will prompt you to enable it prior to completing your first withdrawal.
If you would like more information on how to enable 2FA on your account, please refer to this article here.