Gem::GemcutterUtilities#add_otp_option

# File tmp/rubies/ruby-3.0.5/lib/rubygems/gemcutter_utilities.rb, line 32
def add_otp_option
  add_option('--otp CODE',
             'Digit code for multifactor authentication',
             'You can also use the environment variable GEM_HOST_OTP_CODE') do |value, options|
    options[:otp] = value
  end
end