I am writing a Bash script to store the version number of Virtualbox, but cannot succeed.

My Script is:

#!/bin/bash

installed_virtualbox=$(virtualbox --version) # --version this is what I want to change

I tried

virtualbox --version

virtualbox -v

virtualbox -V

virtualbox --Version

all seems to open the virtualbox instead of output.

virtualbox --help gives the version number, but the output is too long to store in variable and use later.