URGENT!! Adding a Custom Button to Header Dawn Theme

[echosadmn]

Hi there, 

My store website is https://betterbuttlift.com. I would like a custom button, called "Manifesto", on top right section of the website. Upon clicking on the button I'd like it to open a pop-up that shows a body of text. For example it could say "BBL stands for Better Butt Lift not Brazilian Butt lift". 

 In terms of button placement this is what I'd like. 

I'd appreciate any help!!

[jamalsoueidan]

https://developer.mozilla.org/en-US/docs/Web/API/HTMLDialogElement/showModal

[echosadmn]

What am I supposed to do with this? 

[jamalsoueidan]

This shows you the code to use to have a button and modal on your site 🙂

[echosadmn]

I appreciate it, but I can't quite figure it out still. Would you be able to explain more explicitly what you mean? 

Thanks. 

[jamalsoueidan]

Have you ever edit code in shopify themes?