How can I delete all my all backups data

Please note: deleting backups is essentially deleting data (i.e. photos, videos, app data, etc.) on your device. If you are running out of iCloud storage I would advise buying a monthly plan of extra storage instead of having to delete possibly important data on your device. If you are positive that you want to delete backups, then I have one more thing to say. I would not delete any backups off of your device unless you have it backed up on a mac or windows computer. For more information, go here: https://www.imore.com/how-delete-old-icloud-backups

Hope this helps! Have a nice day!