"Directory not empty" when I try to remove a folder from trash

I am going crazy: I can not delete a folder inside the trash of my exteal drive.

The file path is /Volumes/drive_name/.Trashes/501/dir_name/

I tried

sudo rm -R /Volumes/drive_name/.Trashes/501/dir_name/ and

sudo rm -rf /Volumes/drive_name/.Trashes/501/dir_name/ in terminal but every time I get Directory not empty

The directory even shows up in my mac's trash when then the exteal drive is coected, but it does not empty:

How can I delete this folder from the trash? Thanks