I need to see the iPad microphone

I already updated my iPad to the most updated version which is 18.6.2, I can see the karaoke lyrics, however I can’t see the microphone sign, that mean I can’t lower the vocals volume, who has the same problem? Or who can tell me why and how to solve it? I am sure the song is able to be sang, as this is a same song I can see the mic function in my iPhone which is just a iPhone 12pro.

[Re-Titled by Moderator]

Original Title: do not see the microphone