React-native-iap: Tidak terdefinisi bukan fungsi (mengevaluasi 'RNIap.prepare()')

Ketika saya menjalankan react-native run-Android --variant=release, function .prepare() tidak terdefinisi
Tetapi ketika saya menjalankan react-native run-Android, .prepare() adalah sebuah fungsi
android/build.gradle saya

buildscript {
    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.1.3'
        classpath 'com.google.gms:google-services:4.0.1'
  }
}

allprojects {
    repositories {
        mavenLocal()
        jcenter()
        maven {
            url "$rootDir/../node_modules/react-native/android"
        }
        google()

        configurations.all {
            resolutionStrategy {
                force 'com.facebook.android:facebook-android-sdk:4.21.0'
            }
        }
    }
}

ext {
    compileSdkVersion = 27
    buildToolsVersion = '27.0.3'
    minSdkVersion = 16
    targetSdkVersion = 25
}

subprojects {
    afterEvaluate {project ->
        if (project.hasProperty("android") || subproject.plugins.hasPlugin('android-library')) {
            android {
                compileSdkVersion rootProject.ext.compileSdkVersion
                buildToolsVersion rootProject.ext.buildToolsVersion
            }
        }
    }
}

android/app/build.gradle

...
dependencies {
    implementation(project(':react-native-firebase')) {
        transitive = false
    }

    // RNFirebase required dependencies
    implementation "com.google.firebase:firebase-core:16.0.1"
    implementation "com.google.android.gms:play-services-base:15.0.1"

    implementation "com.google.firebase:firebase-config:16.0.0"

    implementation fileTree(dir: "libs", include: ["*.jar"])
    implementation "com.android.support:appcompat-v7:27.1.1"
    implementation "com.facebook.react:react-native:+"  // From node_modules
    implementation project(':react-native-vector-icons')
//    compile project(':react-native-navigation')
    implementation (project(':react-native-device-info')) {
        exclude group: "com.google.android.gms"
    }
    implementation project(':react-native-facebook-login')
    implementation(project(":react-native-google-signin")){
        exclude group: "com.google.android.gms"
    }
    implementation project(':react-native-i18n')
    implementation 'com.google.android.gms:play-services-auth:15.0.1'
    implementation project(':react-native-svg')
    implementation project(':react-native-linear-gradient')
    implementation project(':react-native-text-gradient')
    implementation project(':react-native-iap')
    implementation project(':react-native-fetch-blob')
}
...

Versi reaksi-asli-iap

1.2.4

Platform yang Anda hadapi kesalahannya (IOS atau Android atau keduanya?)

Android

Perilaku yang diharapkan

RNIap.prepare adalah sebuah fungsi

Perilaku sebenarnya

RNIap.prepare tidak ditentukan

Lingkungan yang diuji (Emulator? Perangkat Nyata?)

keduanya

Langkah-langkah untuk mereproduksi perilaku

Jalankan react-native run-Android --variant=release, function .prepare() tidak terdefinisi