Kotlin no text from api

I wanted to load my text from an api in kotlin. I get no errors or exeptions only i get no text.

I got the info from this api: https://min-api.cryptocompare.com/data/price?fsym=ETH&tsyms=BTC,USD,EUR

and i pushed my code to this github repo: https://github.com/robbe-delsoir/Herexamen

This is my MainActivity:

import android.content.Intent
import android.os.Bundle
import android.util.Log
import android.widget.Button
import android.widget.TextView

import androidx.appcompat.app.AppCompatActivity

import retrofit2.Call
import retrofit2.Callback
import retrofit2.Response

import retrofit2.Retrofit
import retrofit2.converter.gson.GsonConverterFactory
import java.lang.StringBuilder

const val Base_Url = "https://min-api.cryptocompare.com/"

class MainActivity : AppCompatActivity() {

    private lateinit var txtId: TextView

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        getMyData();

        val secondActButton = findViewById<Button>(R.id.buttonAbout)
        secondActButton.setOnClickListener{
            val intent = Intent(this, activity_about::class.java)
            startActivity(intent)
        }
        txtId = findViewById(R.id.txtId)

    }

    private fun getMyData() {
        val retrofitBuilder = Retrofit.Builder()
            .addConverterFactory(GsonConverterFactory.create())
            .baseUrl(Base_Url)
            .build()
            .create(ApiInterface::class.java)

        val retrofitData = retrofitBuilder.getData()

        retrofitData.enqueue(object : Callback<MyData?> {
            override fun onResponse(call: Call<MyData?>, response: Response<MyData?>) {

                val responseBody = response.body()
                val myStringBuilder = StringBuilder()
                if (responseBody != null) {
                    myStringBuilder.append(responseBody.BTC)
                }

                txtId.text = myStringBuilder

            }

            override fun onFailure(call: Call<MyData?>, t: Throwable) {
                Log.d("MainActivity", "onFailure: "+t.message)

            }
        })
    }

}

This is the MyData class:

data class MyData(
    val BTC: Double,
    val EUR: Double,
    val USD: Double
)

This is my ApiInterface:

import retrofit2.Call
import retrofit2.http.GET

interface ApiInterface {
    @GET("data/price?fsym=ETH&tsyms=BTC,USD,EUR")

    fun getData(): Call<MyData>
}

Ànd this is my textview where it needs to come in:

<TextView
    android:id="@+id/txtId"
    android:text="Hello"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginStart="212dp"
    android:layout_marginTop="314dp"
    android:layout_marginEnd="167dp"
    android:layout_marginBottom="398dp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

I hope someone could help me! Thanks!

you need to set Internet Permission on AndroidManifest.XML

  <uses-permission android:name="android.permission.INTERNET" />