how to use magic mouse between imac and macbook air

I have an iMac from late 2015 running Monterey and just purchased a MacBook Air 2023 running Sonoma. I want to use a mouse with the MacBook but the mouse with my iMac won't pair with it even though bluetooth is turned on. Is there a way to get it to recognize my mouse or is there some other mouse I could buy that would be compatible with. the MacBook?

Thank you