Normally, if you try the key sequence Alt+1 in xterm, it will output a special character. To enable the Alt key:
Add the following to the .inputrc file in your home directory. Create one if it doesn’t exist already.
set meta-flag on set convert-meta off set output-meta on
Add the following to the .Xdefaults file in your home directory.
XTerm*metaSendsEscape: true XTerm*eightBitInput: false
Open xterm if its not already, and execute the following command in the xterm Window.
xrdb -load ~/.Xdefaults
Restart all xterm windows. The Alt key should work now.
Thank you. That worked for me with my zsh key bindings.