What is the unity channel public key?

I applied unity IAP to use google IAP.

In Unity’s IAP Obfuscator setting, I know what to put in the google play store public key, but I do not know what to put in the Unity Channel Public Key.

If you press the Obfuscate secrets button without entering anything into the Unity Channel Public Key, an error occurs.

@lleo52 looks like it’s for xiaomi