How to integrate autofill in Jetpack Compose

I want to provide some autofill functionality in my app (email and password) that is written completely using Jetpack compose. I came across this blog post and this demo code which I both tried out. Unfortunately, I can't get any popup when interacting with the text fields.

After modifying my code, I ended up using the provided demo. A minimal example looks like this (the ExplicitAutofillTypesDemo composable is taken from the demo code mentioned above without any modification):

class MainActivity: AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        setContent {
            ExplicitAutofillTypesDemo()
        }
    }
}

What am I missing? Do I need to enable it somewhere else? The official compose autofill documentation is not very helpful. I only want to get a autofill popup when touching a text field like in the blog post above.

In my case, the popup was not showing due to the fact that autofill doesn't seem to work with any other provider than Google. The debug log shows the following message:

D/Autofill Status: Autofill popup isn't shown because autofill is not available.
    
    Did you set up autofill?
    1. Go to Settings > System > Languages&input > Advanced > Autofill Service
    2. Pick a service
    
    Did you add an account?
    1. Go to Settings > System > Languages&input > Advanced
    2. Click on the settings icon next to the Autofill Service
    3. Add your account

I tried the Microsoft Authenticator as an example which does not work. When I switch to Google, everything works as intended.