How does this feature work and how do i use it. Is it just for the single note.
1Password Version: Not Provided
Extension Version: Not Provided
OS Version: iOS 10.3.1
Sync Type: Cloud
The one-time password section is for recording one-time password information, so that 1Password can generate TOTP codes for you.
It is probably more useful in most cases to store this information on a login item that is associated with the website the TOTP codes are for, but in some instances it may be helpful to be able to store them inside of other item types (such as Secure Notes).
The TOTP code is not for accessing the Secure Note itself. 1Password does not use TOTP for authentication.