Hi Jeffrey,
Thank you for contacting us about this.
Currently, it is not possible to back up your site externally. Wix is committed to ensuring the safety of your site, we keep multiple backups of each site. Additionally, we created the Site History feature, which automatically creates site revisions every time you save or publish. This means that you can go back to a previous version of your site any time you want.
You can also duplicate your site at any time to create a manual backup in your Wix account. Be aware that the duplicated site is not automatically updated when your update your original site.
We also have options to export data from apps like Wix Stores and Wix CRM.
We are always working to update and improve our products, and your feedback is hugely appreciated.