<floatingActionButton unresolved reference [duplic...

# stackoverflow

[user]

floatingActionButton unresolved reference [duplicate]
I am complete beginner with kotlin and android development and I'm currently following a tutorial to build an app. In this tutorial, the code is written in this way:

code▾

However, when I wirte it, I get unresolved reference error:

my code▾

my code▾

I have done everything...