This repository contains sample data and a tutorial script to get started with the leafkin package. Ideally, you download all files in a zipped folder (through the drop-down menu of the green Code button) and extract the folder on your computer (not extracting will result in an error). If you keep the structure of the files in the extracted folder (i.e. sample data in the "data files" folder and the RStudio project, the tutorial R script and the data files folder in the main folder), the path to the sample data created with the tutorial script should work.
IMPORTANT: Please consult the README.md file in the leafkin repository (link) for help on errors or specific difficulties. Especially the first topic, on leafkin installation, can be useful.