I use okHttp, the onFailure method is called in the Callback. How to fix?

Question

Android

class MainActivity : AppCompatActivity() {

    val okHttpClient: OkHttpClient = OkHttpClient()
    val request: Request = Request.Builder().get().url("http://dev-tasks.alef.im/task-m-001").build()
    val call: okhttp3.Call = okHttpClient.newCall(request)

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
      
        call.enqueue(object : okhttp3.Callback{
            override fun onFailure(call: okhttp3.Call, e: IOException) {
                Log.d("myLog", "onFailure: ")
            }

            override fun onResponse(call: okhttp3.Call, response: okhttp3.Response) {
                Log.d("myLog", "onResponse: ")
            }

        })
    }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.aleftestproject">
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.AlefTestProject">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

I did not immediately notice that you can display the text of the exception. In short, it is this: CLEARTEXT communication to dev-tasks.alef.im not permitted by network security policy

Answer 1

It is very strange that after an hour (sometimes hours) of searching for a solution to the problem, after which I ask a question on Habré, the answer is found by itself and very quickly and this is not the first time. I solved my problem, but in part, you yourself will find out why later. I leave the answer for future generations. It works if onFailure gives a message similar to mine: "CLEARTEXT communication to dev-tasks.alef.im not permitted by network security policy
Information taken from here: https://coderoad.ru/59856341/OkHttp-HTTP-FAILED-ja..
In src/main/res/xml (create a folder)/ you need to create a file network_security_config.xml In the file itself ,
write this:

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <!--Set application-wide security config using base-config tag.-->
    <base-config cleartextTrafficPermitted="true"/>
</network-security-config>

And add this line to your manifest:

<application
     ---
        android:networkSecurityConfig="@xml/network_security_config">

This line is a snag, because I need my "app" to work with android 5, but this line itself is only supported with API level 24. I will most likely look for a different solution.