How to install backups without WP-backend? Special files not included??

Hi,
unfortunately my sites have been hacked and I have no access to the backend where I could install backups.

Is there a tutorial how I can do it via ftp or are there any other ways?

Second question: My backups comprehend everything what can be done with Updraftplus, i.e., I have choosen to save everything what Updraftplus allows to save. But I remember that there may be single files, which are not part of the backups, for example htaccess and robots.txt in the main folder of my website folder. Do I recall correctly?

Thanks,

Martin