Failed to open a session for the virtual machine windows 10

Screenshot I made a new installation of the Oracle VM Virtual manager. Upon starting, I have the following error.

Failed to open a session for the virtual machine windows 10. details:

VT-x is not available (VERR_VMX_NO_VMX).

Result Code:

NS_ERROR_FAILURE (0x80004005)
Component: 
ConsoleWrap
Interface: 
IConsole {872da645-4a9b-1727-bee2-5585105b9eed}

I have checked a few answer on Stackoverflow and google but yet to resolve it. Please I will appreciate your assistance.

I am running Ubuntu 20.04