instance method key

# File actionmailbox/app/controllers/action_mailbox/ingresses/mailgun/inbound_emails_controller.rb, line 79
      def key
        if Rails.application.credentials.dig(:action_mailbox, :mailgun_api_key)
          ActiveSupport::Deprecation.warn(<<-MSG.squish)
            Rails.application.credentials.action_mailbox.api_key is deprecated and will be ignored in Rails 7.0.
            Use Rails.application.credentials.action_mailbox.signing_key instead.
          MSG
          Rails.application.credentials.dig(:action_mailbox, :mailgun_api_key)
        elsif ENV["MAILGUN_INGRESS_API_KEY"]
          ActiveSupport::Deprecation.warn(<<-MSG.squish)
            The MAILGUN_INGRESS_API_KEY environment variable is deprecated and will be ignored in Rails 7.0.
            Use MAILGUN_INGRESS_SIGNING_KEY instead.
          MSG
          ENV["MAILGUN_INGRESS_API_KEY"]
        else
          Rails.application.credentials.dig(:action_mailbox, :mailgun_signing_key) || ENV["MAILGUN_INGRESS_SIGNING_KEY"]
        end
      end