Bookow
https://www.bookow.com/resources.php generates Amazon cover templates, (I use the same template for Ingram without any problems, basically I grab all the files, copy them, then paste them on the Ingram template). The hardest part is going to be the spine.
Grab the PNG, open it up in Canva (I think you can do it) and build your wrap from that template. Or, you can grab a copy of Scribus and create the wrap in Scribus (plus, I think Scribus actually has exporting to epub now, so you could even build a quick print template, use it for both print and epub (with your own CSS file).
Here's the easy peasy way of doing a full-wrap cover:
Find an image for the background, if the image you used for your ebook cover isn't big enough, just pick a solid color that coordinates with your front cover.
From edge to edge (cover that pink bit on the outside of the template) with the base image. Stick your ebook cover on the front. Possibly make adjustments so no text goes into the bleed and is safe inside the trim line. It depends how close to the edge your text is.
Add a box on the back cover that either a coordinating color or white. Use black text for the description. (If you use colored text and something like Photoshop, the text might be a little blurry, especially at anything under 18 pts. Whereas using InDesign or Scribus will embed the font and not treat the file like an image, but a font - it's weird - and you can pretty much do whatever you want with the text copy as long as its in the safe zone.) Add some other fun stuff, like press name, author photo, or anything else to the back bit.
This is the wrap cover I did for Formatting for Print
https://www.amazon.com/Formatting-Print-format-printers-Self-Publishers/dp/1948603160 I don't think it can get any more basic than that, but it works fairly well.
Once you have that base set up, the hardest part is the spine and making sure your text fits within the safe zone and it will line up across all series. The thicker the book, the less you have to worry about fitting the spine.
However, I want to remind anyone considering doing a book with more than 500 print pages, the more pages you have, the more inside margin you will need and there is a hard limit on your outside margin. As you increase that inside margin, the size of the text box decreases and the words have to go somewhere. Where do they go? New pages, so you add more pages and your spine width increases and your inside margins increase. POD will always push through tighter bindings, it's just the nature of the beast, so you already want to have an generous inside margin.
Remember too that traditionally published books have the benefit of an off-set printer and a professional typesetter. They are also using InDesign (or maybe Pagemaker) and have access to a library of fonts. While indies can have access to most of these things, use of an off-set printer is usually cost prohibitive unless they know they will sell several hundred during a year at signings. And it's the off-set printer that makes all the difference because the bindings aren't quite as tight and the inside margins have a lot more wiggle room.