Error in console, function call?

Question

JavaScript

What's wrong? The site has a playbtnclick() function; It starts the game, when I call it from the content_scripts file, it writes this error in the console ((

Answer 1

It says there is no such feature.
Check the correct spelling of the function name, the order of connecting files / modules?

Answer 2

1) Check the scope of the playbtnclick function, i.e. if, after everything has loaded, type window.playbtnclick in the console, the output will show that something intelligible is s.m. point 2, if not, think about it.
2) Check the sequence of loading files and starting handlers