How to control Aperture during an exposure on the Nikon F4?

My confusion stems from the fact there's no aperture dial or control on the camera body. However, there are compatible lenses to the camera without aperture rings. For example: if I were to attach the Nikon F4 with a "Nikon Nikkor 70-300MM f/4-5.6G AF Zoom Lens".

How could I adjust the aperture during an exposure, given the lens does not have a dedicated aperture ring nor does the Nikon F4 have a aperture control?

Does this mean if I were to use a compatible lens without an aperture ring, I could only shoot in Automatic or Shutter Priority modes?

I appreciate your input in advanced.

Try putting it on shutter priority and adjusting the shutter speed until you get the exposure you want.

"Does this mean if I were to use a compatible lens without an aperture ring, I could only shoot in Automatic or Shutter Priority modes?"

Pretty much - yes - there's no other way to control the aperture if you use a G lens. It's Program modes (P, PH) or S only.