Require activation for checkout: Choose whether the above activation rule should be effective in the one page checkout also. If enable then the new user will not be activated before proceeding with checkout.When you click on the text box then all the group will be listed in the drop down menu.
Profile Sections Ordering: You can set the ordering of sections of the user profile.
Frontend Login Methods: You can choose how would you allow the users to login in frontend.
For more information related to otp, follow the below documentation:
Length of OTP: You can set the length of the generated OTP.
OTP validity (s): Here you can set, for how many seconds OTP should be valid.