Steering Gearbox Simple Silly Question

[UniqueOdyssey68]

How/where do I check fluid and fill?
Gearbox installed, connected to steering column/wheel, but no other lines connected. This is so I can steer the wheels as it's pushed around on/off loading trailer or shop.
Or should I not worry about it?

Do these boxes ship empty? Or do they have some lubricant in them. This is a quick ratio PS rebuild box from ECE many years ago. Haven't done anything with it until now, putting the steering, column, firewall booster things together and mock up. Do I fill through the center top hole? The line ports where the red plastic plugs are? I do not see any other port or bolt hole on the sides or bottom. The 4 bolts on the top, is that the top cover?

Thanks for the tips and advice. I just don't want to "ruin" or grind this box when I'm only trying to push and steer it easier around the shop and when it goes to the exhaust shop soon.