Tick checkbox if a certain cell is not empty.

Hello everyone,

Thanks for this awesome forum!

I am new to here and also to VBA. What I am looking for is a way to have a checkbox automatically ticked (CheckBox6.Value = True) if a certain cell is not empty.
To be more precise, it is a form where you choose different options by ticking checkboxes and then enter a money amount in the cells next to the boxes. I cannot link the cells to the boxes because they are already linked to other cells. So I am looking for a formula that looks like this, but I am missing the first part and the correct syntax:

Private Sub ???????
If CELL G 33 = NOT EMPTY?? then
CheckBox6.Value = True
End If
End Sub

I thank you in advance if you could help me with this!
Cheers