Hidden files are preceded by a "." (dot) in front of the filename. To remove hidden files from your FTP account, please follow these steps to configure your FTP tool:

In Filezilla:

1. Click Edit
2. Click Settings
3. Under the Interface settings, click Remote file list
4. Ensure the "Always show hidden file" is checked
5. Click OK
6. Connect to your FTP account
7. Select the file to delete

In File Manager:

Hidden files are displayed by default in File Manager so you can simply select the checkbox for each hidden file and click the Delete button.