Can't use ctrl+shift+c to copy to secondary clipboard

Running I3 without a desktop environment on Debian 12. My terminal is Alacritty and my shell is bash. I am unable to copy into what I assume is the secondary selection clipboard using the default shortcut CTRL+SHIFT+C. I can mark/highlight text by holding down left mouse button and dragging it and it is correctly copied into the primary clipboard which allows me to paste using middle mouse button. If I copy something from for instance a browser using ctrl+c, I am able to paste it into the terminal using CTRL+SHIFT+V. I have tried a different shell, for instance sh and zsh. I have tried different terminal emulators, for instance Alacritty and i3-sensible-terminal. I have tried to search for conflicting shortcuts using grep, I have been unable to find any conflicting shortcuts in X11, Alacritty, I3 config etc. I have also tried using tmux without luck. I have tried to set keybindings manually in the Alacritty config file without luck. Can anyone help point me in the right direction to get my CTRL+SHIFT+C working properly?