将unity安装目录下Editor - Data - PlaybackEngines - AndroidPlayer - Variations - mono - Release - Class.jar拷贝到安卓Project目录下的自己创建的库中的libs文件夹下，并且右键add as library到模块中

安卓目录下，AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.sikiedu.testlibrary">

    <application
        android:allowBackup="true"
        android:supportsRtl="true">
        <activity
            android:name=".MainActivity"
            android:label="UnityAndroidTest"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
            <meta-data android:name="unityplayer.UnityActivity" android:value="true" />
        </activity>
    </application>

</manifest>