Why do you need to ReAuth your Dropbox Account?
Since Dropbox has deprecated API V1, Now we have integrated Dropbox API V2 with InfiniteWP. To continue saving your backups on Dropbox, you need to ReAuth your account.
Please follow the below instructions to connect your Dropbox account with InfiniteWP(which uses API V2)
Go to Protect --> Backups --> Manual --> Create New Backup
Now Select any one site, and Click Enter Details then Click Select Repository.
Choose Dropbox and Enter APP KEY, APP SECRET, ACCESS TOKEN and Save Changes.
Note: You do not need to reschedule all your Dropbox schedules. Reauthenticating your Dropbox account here will do.