HTB Mobile challenge APKrypt

// Telegram : @HTB0X
import java.util.Base64;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.security.Key;

public class HelloWorld {

    public static String decrypt(String str) throws Exception {
        Key generateKey = generateKey();
        Cipher cipher = Cipher.getInstance("AES");
        cipher.init(Cipher.DECRYPT_MODE, generateKey);
        byte[] decodedBytes = Base64.getDecoder().decode(str);
        return new String(cipher.doFinal(decodedBytes), "UTF-8");
    }

    public static Key generateKey() throws Exception {
        return new SecretKeySpec("Dgu8Trf6Ge4Ki9Lb".getBytes(), "AES");
    }

    public static void main(String[] args) {
        try {
            System.out.println(decrypt("k+RLD5J86JRYnluaZLF3Zs/yJrVdVfGo1CQy5k0+tCZDJZTozBWPn2lExQYDHH1l"));
        } catch (Exception e) {
            System.out.println('Something went wrong !!');
        }
    }
}