If you have 2-factor authentication active on your Stripe account, you can still access the app, you’ll just need to follow these steps during the initial setup:
Upon entering your Stripe credentials you will be prompted to enter the 2FA code from Google Authenticator or via SMS.
If you leave the app to retrieve this code, when you return to the app to enter the code, the screen will refresh and a new code will be generated, so if you enter the one you received initially, it will say the code is incorrect.
To get around this, you will need to receive the authentication code via SMS and when it is received on your device, do NOT tap the notification to be taken to the Messages app to view the code, but instead simply expand the notification to view the code and then enter it manually into Charge for Stripe and you should proceed to the final step of connecting your account.
If this sounds too tricky, an alternate method is to momentarily deactivate 2FA on your Stripe account, complete the authentication process in Charge for Stripe and then turn it back on once done.
You can read more about 2FA on your Stripe account here.