API calling using retrofit

// Hilt-Dagger
implementation "com.google.dagger:hilt-android:2.44"
kapt "com.google.dagger:hilt-compiler:2.44"

// Retrofit and GSON Factory & livedata
implementation 'com.google.code.gson:gson:2.9.1'
implementation 'com.squareup.retrofit2:retrofit:2.9.0'
implementation 'com.squareup.retrofit2:converter-gson:2.9.0'

plugins {
    id 'com.android.application'
    id 'org.jetbrains.kotlin.android'
//    id 'com.google.gms.google-services'
    id 'kotlin-kapt'
    id 'dagger.hilt.android.plugin'
}

buildscript {
    dependencies {
//        classpath 'com.google.gms:google-services:4.3.15'
        classpath 'com.google.dagger:hilt-android-gradle-plugin:2.44'
    }
}
// Top-level build file where you can add configuration options common to all sub-projects/modules.
plugins {
    id 'com.android.application' version '8.0.1' apply false
    id 'com.android.library' version '8.0.1' apply false
    id 'org.jetbrains.kotlin.android' version '1.8.20' apply false
}

@HiltAndroidApp
class MainApplication : Application()

// Interface
interface ApiInterface {
    @GET("theme.json")
    fun getThemeData(): Call<ThemeModel>
}

//Object
@Module
@InstallIn(SingletonComponent::class)
object RetrofitInstance {

    @Singleton
    @Provides
    fun retrofit(): Retrofit {
        return Retrofit.Builder().baseUrl("https://applicationsjson.s3.amazonaws.com/ApplicationMaster/Constitution+of+India/")
            .addConverterFactory(GsonConverterFactory.create()).build()
    }

    @Singleton
    @Provides
    fun getApiInterface(): ApiInterface {
        return retrofit().create(ApiInterface::class.java)
    }
}

// MainActivity
@AndroidEntryPoint
class MainActivity : AppCompatActivity()
private lateinit var themeViewModel: ThemeViewModel
themeViewModel = ViewModelProvider(this@SplashActivity)[ThemeViewModel::class.java]
themeViewModel.apiResponse.observe(this@SplashActivity) { authModel ->
    authModel?.let {
        
    }
}
themeViewModel.fetchThemeData()

// ViewModel
@HiltViewModel
class ThemeViewModel @Inject constructor(private val apiService: ApiInterface) : ViewModel() {

    private val _apiResponse = MutableLiveData<ThemeModel>()
    val apiResponse: LiveData<ThemeModel> = _apiResponse

    fun fetchThemeData() {
        apiService.getThemeData().enqueue(object : retrofit2.Callback<ThemeModel?> {
            override fun onResponse(call: Call<ThemeModel?>, response: Response<ThemeModel?>) {
                if (response.isSuccessful) {
                    response.body()?.let {
                        _apiResponse.postValue(it)
                    }
                } else {
                    Log.e("TAG", "onResponse: ${response.errorBody()}")
                }
            }

            override fun onFailure(call: Call<ThemeModel?>, t: Throwable) {
                Log.e("TAG", "onFailure: ${t.message}")
            }
        })
    }
}