Please temporarily deactivate your firewall plugin, then authenticate your cloud storage again.
Backup & Migration Free
Backup & Migration Pro
Overview: Backup & Migration Pro
Backup: Additional Files/Folders
Backup: Back up WordPress Multisites
Migration: Migrate A WordPress Site via Remote Storage
Migration: A Multisite Childsite to A Single WordPress Install
Migration: Migrate WordPress Multisite
Remote Storage: Wasabi: Custom Folder Name
Remote Storage: DigitalOcean Spaces
Tools: Rollback (Auto Backup before Update)
How-to: Set up Incremental Backups
How-to: Migrate A WordPress Site Manually
How-to: Automatically Migrate A WordPress Site
How-to: Create Backup Schedules
How-to: Customize Start Time for Schedule
How-to: Customize Backup for Schedule
How-to: Backup to Multiple Remote Storage
How-to: Restore A WordPress Multisite Network