I have a Virtual Box machine with Ubuntu. I need to send Ctrl+Alt+F1 to guest machine, but when I press them it is captured by host. How can I fix it ?
You can go to fullscreen in the guest OS by pressing Host+F1. The default host key is Right Ctrl.
Once inside the full screen of Guest OS, try sending Ctrl+Alt+F1. It should be captured as desired.
Right Ctrl+F1 worked for me without going into fullscreen