Auto-resize guest display

[CYANiDE]

Hey guys!
Auto-resize guest display feature is grayed out means unable to use on my Kali Linux vm. Any solution?

Info:
1. Windows host
2. Kali linux guest
3. Kali linux, Virtual box and extension pack all are updated. Please help if possible

[scottgus1]

Guest Additions need to be installed in the Kali guest for "Auto-resize guest display" to work.

[CYANiDE]

Guest Additions need to be installed in the Kali guest for "Auto-resize guest display" to work.

Can you guide me through please?

[scottgus1]

While Kali is running, click the Devices menu in the guest's Virtualbox window.
Click "Insert Guest Additions CD Image".
Open Kali's CD drive.
Run the Linux installer for Guest Additions.