audio example does not compile

[PaulskPt]

Using a M5Stack Core2 device

See the combined screenshot

.
The scetch audio.ino generates the following error:

According to the instructions in the top of audio.ino I installed the following libraries:
git clone https://github.com/earlephilhower/ESP8266Audio
git clone https://github.com/Gianbacchio/ESP8266_Spiram

Class AudioOutputI2S:

The only class that has a member getLevel() is AquestTalkTTS. See screenshot below: