How can I see which application is using Bin, so that it cannot be emptied? How can I see which application is using the Bin, so that it cannot be emptied?

I've so many tasks and projects open, so I'd rather not restart the macOS Catalina.

I have tried looking in Activity Monitor, but couldn't figure it out.
According to answers on the Ask Different question Cannot empty trash, you can use either

ps -eal | grep $(fuser ~/.Trash)


or 

lsof | grep Trash


in the Terminal to find out which process is using the Trash.