Follow$-$up question to "How can I implement the Open Sea Map API in an Android Studio app with Kotlin?"

I got some help here:

https:$//$www$.$chegg.com$/$homework$-$help$/$questions$-$and$-$answers$/$implement$-$open$-$sea$-$map$-$api$-$android$-$studio$-$app$-$kotlin$-$looking$-$tutorials$-$online$-$including$-$os$-$q$151804422$

However, when I follow the steps in this tutorial, I get the following error:

"Type mismatch: inferred type is OnlineTileSourceBase but MapTileProviderBase! was expected"

How do I fix this?