how can we get apple music for free on a laptop

Apple Music is a prescription service, you don't get it for free, you pay the subscription and it will be subscribed to your Apple ID and as long as the Apple ID is the same as your phone or iPad, you'll be able to listen to it on your computer as well. If you're using a PC, you download iTunes and you get Apple Music through there. If you're using a Mac, it's either going to be iTunes or Music depending on which version of MacOS you have installed on your Mac