Inspections - How to plug?

I'm preparing for the rough inspection of a bathroom basement. I've been told I need to "plug the system and fill the system to 5 feet". I have a sink, toilet, shower draining below slab to sewage basin.

How do I do this? Insert test plugs in the sink, toilet, and shower and then fill the system up until the vent has 5ft of water in it?

Does this mean I need a cleanout 5+feet up to be able to fill?

I guess this also means I need to plug the sewage basin inlet too, right?

If you are just roughing in these fixtures, then it should be pretty easy to plug the lines as you can just cap them off with pvc caps. (I assume that you have not actually installed the fixtures yet.) However, I am not sure how you address the basin. I have never installed one of those. I expect the basin is supposed to be water tight though so that you would fill that as well. You can fill the system throught he vent pipe from the roof until the inspector is convinced that you are 5 feet above your new work. Perhaps someone here will have more experince with sewage ejectors and pits.

test

An inflatable or wing nut type plug in the pipe inside the basin, and orange push on, or in, caps at the fixture openings will plug the pipes. Then you can either cut the pipe at the 5' level and fill it or fill the pipe all the way to the roof.

Thanks all.
The vent is shared with the rest of the house, so I'd have a lot of plugging to do if I filled from the roof, so I'm gonna have to cut into the pipe.

I left one of the fittings uncemented, so I guess I can fill from that point.

Thanks!