Audio doesn't work

[ttttinyfish]

I follow the giude to install the Catalina 10.15.7, and everything work well except audio. I try to inject layout-id but failed.

My laptop info:
cpu: i5-6200u
audio: alc-256

[ttttinyfish]

I solved the problem by cleaning the nvram.
1.use "nvram -xp" to check the value.
2.use "nvram -d keyname" to remove the value of nvram.
3. inject the layou-id 13.
4. restart