UNIX for Beginners Questions & Answers

For keybinds, have used bbkeys with blackbox. Now, I can not compile it on debian 10, so I try to use xbindkeys
It work OK with commands, but not with blackbox actions, such as Alt+F4 to "close window", or Alt+Tab to "switch tasks", and so. I have searched the internet but I can't find data about it. Can someone help me?
Thanks Here some lines from the config file ~/.xbindkeysrc

Code:

#Work ok: 

"thunar"
  Control + e

"xterm"
  Control + t 


# The next lines (without #) no not work any 


"Close"
 Alt + F4 

#"[Close]" 
#Alt + F4 


#"(Close)" 
# Alt + F4 

"NextWindow"
  Alt + Tab

Looks like your system does not like your use of "Alt".

I think it is a good idea for you to print out your current keybinding list.

In the meantime, you might also consider this listing example (maybe not helpful because this is from macOS not Debian):

Code:

  Key Modifiers 
    ^ : Ctrl 
    $ : Shift 
    ~ : Option (Alt) 
    @ : Command (Apple) 
    # : Numeric Keypad

Note the use of "Option" above. Maybe try something that instead for fun in the meantime (or just list your keybindings so you know what is mapped now)?

Note2 (see also): xbindkeys giving wrong mapping information