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Do not use backup plugins on free hosting.
Your hosting account will get suspended easily.

If you are try to perform a backup, this is the preferred way

How to backup your website

Good website administration requires making backups of your account regularly and storing them somewhere safe yourself. You also need to download backups in order to migrate website to other hosting accounts. InfinityFree does not create or store any backups of free hosting accounts. It’s your responsibility to regularly create backups, and to store them somewhere safely. Backup your website files The best way to backup your website files is by downloading them using a desktop FTP client. Op…