Hi wolfie,
I am the mysterious user, and you are welcome

I think the key to getting them to eat veggies is persistence. Offer them every day so they are used to seeing the strange things in their home.
These guys/gals are also very curious and their curiosity sometimes gets the best of them if they see YOU eating the veggies and saying mmmmm making a big deal out of how good they are.
Some like them chopped, some like them in a dish, some on a plate(like my guys with their chopped veggies)...clip leafy greens to the side of the cage at the end of a perch they frequent. You might even try clipping to the OUTSIDE of cage for a while so they can nibble through the bars. Might seem less threatening on the outside?
Kale is an excellent choice nutrition wise as are beet greens if you can find them. Mine luv both
My 2 don't like cooked carrots, but they love them raw and chopped up fine in a mini chopper, or by hand if a chopper is not available.
Mine won't eat their sweet potatoes fully cooked and mushy, so I partially cook them in the microwave so they are still a bit crunchy. Sweet potatoes are more nutritious cooked..and more nutritious still cooked with skins on
I chop carrots or sweet potatoes and kale..sometimes a little brocolli. They prefer them on a small saucer or cool whip container lid over putting them in a dish.
You might also try sprinkling a little of their seed on top while they are watching. Again..curiosity gets the best of them sometimes. lol
Again...just keep on trying, and if one way of presenting them doesn't work after you've given it a good go, try another way of presenting them.
Good luck..and keep us posted on the babies to be and the parents