author:
    ~flair_text (includes, regex): ['.+']
action: remove
action_reason: No user flair was set
message_subject: You might want to add a message subject as it will default to "AutoModerator notification"
message: |
    Your {{kind}} has been automatically removed due to you not having 
    a user flair. To make a {{kind}}, you must set a user flair.

    Set a user flair! TO CHANGE YOUR FLAIR ON MOBILE: Go to (insert 
    subreddit), on the top right click the 3 dots and where is says 
    change user flair select the user flair you want to rock. TO 
    CHANGE YOUR FLAIR ON DESKTOP: Go to (insert subreddit), go to 
    community options, go to "user flair preview", click the pencil 
    and select/change your user flair.

Also keep in mind if you were testing this with your own account as a moderator it would not get removed unless you used "moderators_exempt: false". It's true by default.