How do I backup data from a broken iPhone to a MacBook?

It is too late to back up the phone now. You should have backed it up to iCloud or to your MacBook when it was working.

If you were synchronizing data with iCloud (e.g., using iCloud Photos), that data may have made it to iCloud, from where you could synchronize it to a repaired or new phone, synchronize it to your Mac, or access it via the iCloud Web interface https://www.icloud.com . Note that if your phone was not set to synchronize data with iCloud, you won't be able to turn synchronization on "after the fact" to save your data.

kennedi11 wrote:

how can I backup things from my iPhone to my MacBook if the screen is broken ps: please help

You can't. Backups MUST take place before something goes wrong. This is why Apple makes it so simple to backup to iCloud nightly when the phone is plugged into charge and connected to Wifi. It's too late to backup a device after it's broken.