If you use Google Authenticator or Authy to generate 2-factor authentication (2FA) codes and you're unable to access your account, you can easily restore the 2FA codes for your account if you saved the secret seed (recovery key) provided when setting up your 2FA device.
You may have written down this secret or saved it to a Cloud/USB drive. 

You can find instruction on how to setup 2FA manually (using the recovery key) here.

Originally, to start generating codes you would have scanned a QR code with your phone, or copied it. If you activated 2FA with manual entry. The following steps will show you how to generate these codes from only the secret seed:

When you open the app, add a new seed by pressing the red plus in the bottom right corner. Select “Enter a provided key” from the menu that appears.

In the form that is shown to you, fill out the account name with something that describes this account (such as "Quidax") and type the seed into the field for the key.

If you've lost your authentication device and do not have access to the secret seed, please find the recovery steps below.

Create a support ticket and provide the following information:

i. Take a picture clearly showing your face and holding a valid government-issued identity document (same as the ID used if your account is verified) and a plain paper with Quidax and the current date written on it.
ii. Confirm the value of your last deposit (Local currency or Cryptocurrency), you can confirm this from deposit notifications in your mailbox.