Add these lines to your Emacs initialization file with your binding of preference.
(keymap-set org-agenda-mode-map "C-o" #'casual-agenda-tmenu)
Use these bindings to configure Org Agenda to be consistent with bindings used by Casual Agenda. This is optional.
; bindings to make jumping consistent between Org Agenda and Casual Agenda (keymap-set org-agenda-mode-map "M-j" #'org-agenda-clock-goto) (keymap-set org-agenda-mode-map "J" #'bookmark-jump)