Frida not hooking Android method, implmentation unchanged

Question

I'm trying to hook a method in an app for which I don't know the source code but I have the APK.

I loaded the APK inside Android Studio and found that in the classes2.dex file there is a method named posteitaliane.posteapp.appposteid.home.HomeAct.onBackPressed() which triggers a dialog box saying "Are you sure you want to quit the app" or along the lines of that.

Here's the screenshot of the method being shown in Android Studio:

I wrote this simple script just to test that simply prints to the console when the method is called:

Java.perform(function() {
    var homeActClass = Java.use("posteitaliane.posteapp.appposteid.home.HomeAct");
    homeActClass.onBackPressed.implementation = function(){
        console.log("[ + ] onBackPressed called! ");
        this.onBackPressed(); //Call the original function
    }
});

Here is the Python script that loads the script and starts Frida:

import frida, sys

with open("script_hook.js") as f:
        jscode = f.read()
process = frida.get_usb_device().attach('PosteID')
script = process.create_script(jscode)
print('[ * ] Attaching to PosteID application...')
script.load()
sys.stdin.read()

When I'm on the home screen, and I'm sure that the class is right because the Android Studio profiler tells me this:

If I try to go back the dialog box shows up, but nothing gets printed to the console.

I can't understand what I'm doing wrong here.