Hide and Unhide a Combobox based on Criteria met in another Combobox

I would like assistance with VBA code to Unhide a combobox set to visible = false based on the value of another combobox.

For example:

Combobox 1 contains a list of values, Blank, Not Required, Letter Type 1, Letter Type 2, etc.

Combobox 2 contains a list of signatories

I would like Combobox 2 to be visible only if the selection from Combobox 1 is not equal to blank or equal to Not Required

Any assistance will be greatly appreciated.

thank you very much for the code. This worked a treat!