[ubuntu] Issues with virtualbox after installation

Hello Everyone, I recently installed virtualbox on my ubuntu 16.04 OS by typing "sudo apt-get install virtualbox" but once it finished installing, there was a message saying that secure boot is enabled and when i try opening it using the command "virtualbox" I get the following message:

WARNING: The character device /dev/vboxdrv does not exist.
Please install the virtualbox-dkms package and the appropriate headers, most likely linux-headers-generic.
You will not be able to start VMs until this problem is fixed.

Edit, after removing lock and running "sudo dpkg --configure -a" I got the following:

Your system has UEFI Secure Boot enabled.
│
│ UEFI Secure Boot is not compatible with the use of third-party drivers.
│
│ The system will assist you in toggling UEFI Secure Boot. To ensure that
│ this change is being made by you as an authorized user, and not by an
│ attacker, you must choose a password now and then use the same password
│ after reboot to confirm the change.
│
│ If you choose to proceed but do not confirm the password upon reboot,
│ Ubuntu will still be able to boot on your system but the Secure Boot
│ state will not be changed.
│
│ If Secure Boot remains enabled on your system, your system may still