Android Studio Kotlin で okhttp3 が unresolved reference になる

FirstFragment.kt で import okhttp3.* をすると okhttp 部が赤文字になり、Unresolved reference: okhttp3 のエラーが出ます。
検索して出た情報から下記は試しましたが同様の結果になりました。

build.gradle の implementation を compile に変える
クリーンビルド

正しい import の方法を教えていただきたいです。

FirstFragment.kt

Kotlin
1package com.example.test_application
2
3import android.os.Bundle
4import androidx.fragment.app.Fragment
5import android.view.LayoutInflater
6import android.view.View
7import android.view.ViewGroup
8import androidx.navigation.fragment.findNavController
9import com.example.test_application.databinding.FragmentFirstBinding
10import java.io.IOException
11import okhttp3.*
12
13/**
14 * A simple [Fragment] subclass as the default destination in the navigation.
15 */
16class FirstFragment : Fragment() {
17
18    private var _binding: FragmentFirstBinding? = null
19
20    // This property is only valid between onCreateView and
21    // onDestroyView.
22    private val binding get() = _binding!!
23
24    override fun onCreateView(
25            inflater: LayoutInflater, container: ViewGroup?,
26            savedInstanceState: Bundle?
27    ): View? {
28
29        _binding = FragmentFirstBinding.inflate(inflater, container, false)
30        return binding.root
31
32    }
33
34    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
35        super.onViewCreated(view, savedInstanceState)
36
37        binding.buttonFirst.setOnClickListener {
38            findNavController().navigate(R.id.action_FirstFragment_to_SecondFragment)
39        }
40    }
41
42    private val client = OkHttpClient.Builder()
43        .connectTimeout(CONNECTION_TIMEOUT_MILLISECONDS.toLong(), TimeUnit.MILLISECONDS)
44        .readTimeout(READ_TIMEOUT_MILLISECONDS.toLong(), TimeUnit.MILLISECONDS)
45        .build()
46
47    fun startGetRequest() {
48        val request = Request.Builder()
49            .utl("https://482f.net/api/regalias")
50            .build()
51        client.newCall(request).enqueue(object: Callback {
52             fun onResponse(call: Call, response: Response) {
53                val responseBody = response.body?.string().orEmpty()
54                Log.println(responseBody)
55            }
56             fun onFailure(call: Call, e: IOException) {
57                Log.e("Error", e.toString())
58            }
59        })
60    }
61
62    override fun onDestroyView() {
63        super.onDestroyView()
64        _binding = null
65    }
66}

build.gradle (:app)

gradle
1plugins {
2    id 'com.android.application'
3    id 'org.jetbrains.kotlin.android'
4}
5
6android {
7    namespace 'com.example.test_application'
8    compileSdk 32
9
10    defaultConfig {
11        applicationId "com.example.test_application"
12        minSdk 30
13        targetSdk 32
14        versionCode 1
15        versionName "1.0"
16
17        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
18    }
19
20    buildTypes {
21        release {
22            minifyEnabled false
23            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
24        }
25    }
26    compileOptions {
27        sourceCompatibility JavaVersion.VERSION_1_8
28        targetCompatibility JavaVersion.VERSION_1_8
29    }
30    kotlinOptions {
31        jvmTarget = '1.8'
32    }
33    buildFeatures {
34        viewBinding true
35    }
36}
37
38dependencies {
39
40    implementation 'androidx.core:core-ktx:1.7.0'
41    implementation 'androidx.appcompat:appcompat:1.4.1'
42    implementation 'com.google.android.material:material:1.5.0'
43    implementation 'androidx.constraintlayout:constraintlayout:2.1.3'
44    implementation 'androidx.navigation:navigation-fragment-ktx:2.4.1'
45    implementation 'androidx.navigation:navigation-ui-ktx:2.4.1'
46    testImplementation 'junit:junit:4.13.2'
47    androidTestImplementation 'androidx.test.ext:junit:1.1.3'
48    androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
49
50    implementation 'com.squareup.okhttp3:okhttp:4.10.0'
51}