Automated Direct Message express user consent



I was wondering what it meant for a user to provide express consent to send or receive automated direct messages as described here:

With express user consent, automation of Direct Messaging is permitted. If your application sends or facilitates automated Direct Messages, users must request or otherwise indicate an intent to send or receive Direct Messages in advance. Authenticating into an app is not sufficient user consent.

In efforts to prevent spam and protect our users from potentially malicious activity, we discourage sending links in the body of an automated Direct Message, and the action may be denied.

It mentions that a user authorizing a twitter app isn’t enough, but then how does the user provide “express user content” to send or receive automated direct messages

If I were building a twitter app that allows an account to authorize and then automate it sending direct messages but only when a user actively engages in Direct Messaging with it, how do I prevent the Twitter API from blocking this. What do I do to provide express user consent from the account that’s authorizing to send automated messages and from any account that’s receiving them?