Find iPhone on another MacBook is not showing my MacBook's old location I lost my MacBook around 18 hours ago. When I log into Find iPhone on another MacBook, it is not showing me the last location of my MacBook. 

Why would this be? Can I resolve this?
It seems like you didn't turn on that feature or you turned it off, which can be done in the settings. If this is the case, then it's not possible to turn this feature back on if the MacBook is already lost. 

I recommend turning on Lost Mode if you haven't already.