In Firebase Authentication can we change K icon (Choose different account), When we click button pop up shown choose different login account in this pop up message on top kodular icon shown can we change this icon.
What do you mean? It makes no sense for me.
That K icon (of Kodular) is only if you have not set any custom App Icon.
Set your App Icon and it ( K icon ) will be replaced with your App Icon.
And App Icon is not visible in Companion.
Export your .apk and then Test.