How do I apply Apple ID verification on an iPod touch running iOS 6.1.6? I've reset my iPod Touch running iOS 6.1.6. Now every time I try to login to iTunes after putting in my Apple ID and password it asks for an Apple ID verification code, which has been texted to my phone.

However there is no place coming up to submit this verification code.
Append the verification code to the end of your usual password, then attempt to sign in. This is necessary on login prompts which don't support 2FA, such as those on older versions of iOS.