I want to make something clear about the 2FA and what people are yet to understand.
THE IMPORTANCE OF SAVING YOUR 2FA KEY when setting up a 2FA security.
Why you are asked to save your 2FA key is that, in case of future occurrence, lost of phone, of malfunction of Authenticator app.
So the most important thing to do before you scan the barcode of the 2FA, is to first save the 2FA key associated to that barcode/account.
If for example you had copy the 2FA key and save somewhere before scanning the barcode, there is opportunity to use it to setup another one, if you lost your phone, you just simply put that KEY on the option on Google Auth or AUTHY where it says input key, instead of Scanning Barcode.
Please note that 2FA KEY is different from 2FA code.
A 2FA Key is the string of numbers associated to your account that enables you to set up a 2FA to secure your account. While a 2FA Code is the 6digit code generated by the 2FA Authenticator that will enable you sign in to your account.
So it is very important to save the key associated to your account before scanning the barcode, because if you scan the barcode without saving such key, there is no way you can get the key again.
On permission.io the 2FA is very easy and clear to enable you save before proceeding to scan the barcode (And instructions was made on the said 2FA page).