QR Code page using Flexbox

I am most proud of developing a better understanding of how images are supposed to be coded and how to size/position them properly in order to make it fit within a webpage. What I would do differently is not rely on another piece of code from a separate unrelated project as I would rather try and learn to make a project completely from scratch.

I would like some help on how to get where it says "Challenge by Frontend Mentor. Coded by " to the bottom of the page. Something told me that declaimer belonged on the bottom of the page rather than being embedded within the component itself. I left it as is as I felt I lacked the knowledge on how to do so. Other ways to optimize the amount of code needed would also be helpful.