In Objects and Animation:
Right Click on the first Key Frame of the Object to be Faded and Add 3 Key Frames or
Click on the “+” icon 3 times or
Press “Insert” key on keyboard 3 times
Re position the Key Frames as required
Change Opacity of Key Frame 1 to Zero
Change Opacity of Key Frame 2 to 100
Change Opacity of Key Frame 3 to 100
Change Opacity of Key Frame 4 to Zero