Save `ox-tufte-latex.el` in a directory. Be `PATH` the path of this directory. 

Add this to your init:

```elisp
  (use-package ox-tufte-latex
    :ensure nil
    :init (add-to-list 'load-path "PATH")
    )
```
`use-package` is installed by default in Emacs 29. Below Emacs 29, `use-package` installation is required.

Note: for html exports there is [org-tufte][1]


  [1]: https://github.com/Zilong-Li/org-tufte