There are a few ways to cancel the Google prompt:
Open the Google app, Tap the Menu icon in the top left corner > Settings > tap on your account > Privacy > turn off the “Ok Google” hotword.
On your Android phone or tablet, open the Google app .
At the top left, tap your profile picture or initial.
Tap Voice Match.
Turn off Hey Google.
If you're using Gboard, you can turn off "Ok Google" in Gboard settings:
On your Android phone or tablet, open any app that you can type in, like Gmail or Keep.
Tap where you can start typing.
At the top of your keyboard, touch and hold Preferences .
Tap Voice input.
At the bottom, turn off Enable "Ok Google" detection.