Implementing code gives java classes, not kotlin as in this git repo

[GroovinFlow]

after:
implementation 'com.daandtu:android-web-scraper:1.0.1'
it adds the library, but it's not kotlin. All libraries files are .java and I'm assuming the implementation is not up to date as in this git repo where it says 100% kotlin. This is a problem for me because I am building pure kotlin KMM project.