RetrofitSinglton.kt

object MyApi {

    private const val BASE_URL = " https://www.MYAPI.com/"

    private val moshi = Moshi.Builder()
        .add(KotlinJsonAdapterFactory())
        .build()

    private val retrofit = Retrofit.Builder()
        .addConverterFactory(MoshiConverterFactory.create(moshi))
        .addCallAdapterFactory(CoroutineCallAdapterFactory())
        .client(clientBuilder.build())
        .baseUrl(BASE_URL)
        .build()

    val retrofitService: MyApiService by lazy {
        retrofit().create(MyApiService::class.java)
    }

    //If you want more service just add more val such as
    val otherService: MyOtherService by lazy {
        retrofit().create(MyOtherService::class.java
    }

}

//To use it you just need to do:
MyApi.retrofitService
MyApi.otherService