You can use the following link to install the user script: https://github.com/entropyofchaos/NHK-Easy-Practice-With-WaniKani/raw/main/NhkEasyPracticeWithWaniKani.user.js
Alternatively, you can click on the script NhkEasyPracticeWithWaniKani.user.js and then click the Raw button.
Once the script is installed using a script manager like Tampermonkey, you will be prompted to enter your WaniKani API Token when loading NHK News.
Here is a link to the WaniKani Community forum in if you need to contact me about this repository or would like more detailed instructions on how to use this script. https://community.wanikani.com/t/userscript-nhk-easy-practice-with-wanikani-or-any-website-that-uses-ruby/49590/51