Paperback Book Formatting & Design Help

I have written a book for paperback to submit to Amazon. It is 9 by 6 and will be black and white. I have created a nice book cover in ChatGPT, but I cannot match the dimensions properly from what the book cover looks like to how it should look for Amazon's guidelines... (Budget: $30 - $250 USD, Jobs: Adobe Creative Cloud, Adobe Illustrator, Adobe InDesign, Adobe Photoshop, Amazon Kindle, Book Design, eBooks, Graphic Design, Print Design, Publishing)