问如何使用Retrofit的挂起函数的AS 4.0和组合启用？

EN

buildscript {
    ext.kotlin_version = "1.3.61"
    ext.compose_version = '0.1.0-dev03'

    repositories {
        google()
        jcenter()
        maven { url 'https://dl.bintray.com/kotlin/kotlin-eap' }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:4.0.0-alpha06'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"

    }
}

allprojects {
    repositories {
        google()
        jcenter()
        maven { url 'https://dl.bintray.com/kotlin/kotlin-eap' }
    }
}

task clean (type: Delete) {
    delete rootProject.buildDir
}

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'
apply plugin: 'kotlin-kapt'

android {
    compileSdkVersion 29
    buildToolsVersion "29.0.2"

    defaultConfig {
        applicationId "com.example.test"
        minSdkVersion 29
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
    kotlinOptions {
        jvmTarget = '1.8'
    }
    buildFeatures {
        compose true
    }

}


dependencies {
    def room_version = "2.2.2"
    def lifecycle_version = "2.2.0-rc03"

    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.2'
    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.3.0'

    implementation 'androidx.appcompat:appcompat:1.1.0'
    implementation 'androidx.core:core-ktx:1.1.0'

    implementation "androidx.compose:compose-runtime:$compose_version"
    implementation "androidx.ui:ui-framework:$compose_version"
    implementation "androidx.ui:ui-layout:$compose_version"
    implementation "androidx.ui:ui-material:$compose_version"
    implementation "androidx.ui:ui-foundation:$compose_version"
    implementation "androidx.ui:ui-animation:$compose_version"
    implementation "androidx.ui:ui-tooling:$compose_version"

    implementation "androidx.lifecycle:lifecycle-extensions:$lifecycle_version"
    implementation "androidx.lifecycle:lifecycle-livedata-ktx:$lifecycle_version"
    implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_version"
    implementation "androidx.fragment:fragment-ktx:1.2.0-rc03"

    implementation "com.squareup.retrofit2:retrofit:2.6.2"
    implementation "com.squareup.retrofit2:converter-moshi:2.4.0"
    implementation 'com.squareup.okhttp3:okhttp:4.2.1'
    implementation 'com.squareup.okhttp3:logging-interceptor:4.2.1'
    compileOnly 'org.glassfish:javax.annotation:10.0-b28'

    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
}

import com.example.test.data.response.SnapshotResponse
import retrofit2.Call
import retrofit2.http.GET
import retrofit2.http.Header

interface ApiService {
    @GET("/login")
    suspend fun login(@Header("Authorization") credentials: String): SnapshotResponse
}

java.lang.IllegalArgumentException: HTTP method annotation is required (e.g., @GET, @POST, etc.) 

@GET("/login")
fun login(@Header("Authorization") credentials: String): Call<SnapshotResponse>