Sharepoint Groups Back-Up

Hi all,

Our sharepoint group at work has critical data for us and that's why we want to back up the data there constantly, dynamic lists are also available in this group. How can we backup it safely? Also, for example, if the data in the main group is gone, will the dynamic data in the backup file also be lost? Because as far as I know, if the main group that xlsx files are connected to is deleted, these files cannot be accessed even if a backup is made. 

Thank you for your support in advance !