Hello, Dimitris,
Thank you for reaching out to us.
Please provide screenshots of your settings for Facebook / Google Login via the Private Content area, and temporary wp-admin and FTP access.
To provide wp-admin access, you can create a new user account with administrator role via the Dashboard, and provide us with the username and password via the Private Content area.
To create FTP access, please contact your hosting provider for assistance.
Kind Regards,
8theme team