I bought the backup extension , I import into the backend and I create a folder backups in my domain but when I click Create A New backup always displays me
  • [2015-02-13 10:41:45] - Starting the backup process...
  • [2015-02-13 10:41:45] - Checking to see if the storage directory exists...
  • [2015-02-13 10:41:45] - The storage directory does not exist, trying to create it...
  • [2015-02-13 10:41:45] - Unable to create the directory, please check the permissions!
Did you set the correct path to the backup folder in the extension settings ?
Also, make sure the backup folder isn't located at same level with mailwizz files, if mailwizz is located in /home/name/public_html the backup folder has to be one level up, /home/name/backups.
Make sure it's chmoded to 0777 recursive.

Thank you
it's good I installed the backup and I created one but when I click on download it just opens the page in a new window
It's pretty active, but when you click it, the zip archive, which isn't in a public folder, has to be loaded by the app and make it available for download. In order for this to happen, all permissions have to be correct and your server should handle preparing and downloading a big file, whatever failure will simply refresh the page.
That's the reason why i told you that is easier to simply download it from FTP.
with the backup extension , I'm wondering how to deploy my backup to a new MailWizz install (on a new domain with all DB and settings exactly same)?