My two grew up without natural sunlight for the first 6ish months of their life? They were fine. I was staying in someone's home and the room I was given didn't have curtains and the glass windows had some kind of wallpaper pasted on them to block out the light. It was too hot to open the window so I had to wait until the cooler months to let them enjoy sunlight.
Now as a requirement, as long as they're getting vitamin d from their diet / supplements, it should be okay. From an enrichment point of view, I think natural sunlight makes a huuuuuge difference. I know a window blocks out UV, but still, my birds are much happier with sunlight through a window than without. That being said, as long as your room is bright enough with lightbulbs, they won't be too fussed.
Also, you're doing it for a good reason: to tame and be closer to them. Once they're tame, give them some window time, they get much happier looking outside at the world and nature and animals. My two will sing their little hearts out when they're by the window.