Q: Cannot empty trash?

I have an external HDD connected all the time to my iMac, and there were various items there that I deleted over the time. The hdd has 2 partitions, both have been formated on this mac to ExFat.

When I try to securely empty the trash, it deletes some of its contents, but there are many left, and I get the message, and I get the message "Action could not be completed, you don't have access to some of the items."

I don't know what to do, since there are about 200gb in the trash, and I need to delete them