安卓导依赖包出现问题，说build.gradle中的android()没有签名

plugins {
id 'com.android.application'
}

android {
compileSdk 31

defaultConfig {
    applicationId "com.example.hehaisystem"
    minSdk 21
    targetSdk 31
    versionCode 1
    versionName "1.0"

    //添加如下配置 开启annotation processor
    javaCompileOptions {
        annotationProcessorOptions {
            includeCompileClasspath true
        }
    }

    testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}

buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
    }
}
compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
}

}

没有生成keystore文件