I cannot recommend this book in this format read by this narrator more.
A Connecticut Yankee in King Arthur’s Court is a 1889 novel written by Mark Twain, a.k.a. Samuel Clemens, where an engineer from Connecticut named Hank Morgan is transported to the time of King Arthur due to a blow to the head. In stereotypical New England Yankee fashion he applies his knowledge from 19th century America to transform Arthur’s 6th century England. The various stories that make up the book are funny, frustrating, and too close to some of what we’re experiencing.
Sadly, Audible is the only outlet that has Nick Offerman’s narration. Libro.fm has the book with other narrators (link your local independent bookstore with your Libro.fm account) as does the Internet Archive.
Want to read it as an ebook? The Standard Ebooks edition is a great free starting point. I’m sure your local U.S. library has it in print.