I tried in many ways but they just prefer seeds.

If there's one thing I've learned about animals IN GENERAL, it's that they're fickle. If animals don't like something, they're not going to eat it. However, I've never known birds to avoid fruits and veggies. Are they perhaps too large? Try cutting them smaller if they are. Also, you may want to consider a variety of options. Some animals like some produce and dislike others. Animals are just like humans. Good luck!