Need help with date on calendar - using Qualtrics canned question with Javascript

The calendar used by the Qualtrics library question isn't very good. I recommend using flatpickr instead. It is better in every way. There are a number of Community posts about it.
If you find you need to do date arithmetic, I recommend using moment.js for that.

I was pretty sure that's what you were going to say as I had rest many of your posts before I asked.
I am not against flatpickr but I don't understand it. I went to the website. I tried to follow but I am not good at JS at all. I can really only do some basics.
Could you help get me started? 😳

This post has the basics: https://www.qualtrics.com/community/discussion/comment/23126#Comment_23126

OK. I really appreciate it. I don't even feel like I am close.
Here is where I am at.
This is in the Header:

That seems fine. Then in my actual question which is a text entry I have:
Which of course gives me an error. I have to be missing a space or a character somewhere.
Qualtrics.SurveyEngine.addOnReady(function(){
/jQuery("#"+this.questionId+" .InputText").flatpickr({
enableTime:true,
dateFormat: "mm-dd-YYYY",
  disable: [
    {
      from: "01-01-1901",
      to: "08-14-2025"
    },
    {
      from: "07-02-2021",
      to: "07-01-2025"
    }
  ]
}

https://www.qualtrics.com/community/discussion/comment/28132#Comment_28132That isn't the header. That is Custom CSS, but you've put JavaScript instead of CSS there. In the header should be the html: