I have installed Ubuntu 18.04 in Oracle virtual box but I am not able to install Guest Additions to maximize the Ubuntu screen.
I have run the following command in the Ubuntu terminal but when I click "Devices => Insert Guest Addition CD Image" I get an error that unable to insert virtual optical disk. How to fix the issue ? I need to maximize the Ubuntu screen.
sudo apt install build-essential dkms linux-headers-$(uname -r)