Birds need to go to you on their own terms, in their own time. If you grab them, they will try to run away. But if you sit quietly with some treats (like mealworms), they will come to you. When they realize that you will not hurt them or grab them, they will eventually come closer and closer.
Mine sit on my lap and sleep while I pet them. Sometimes, they stay for a minute, sometimes for 40 minutes. But I can't make them come to me. They have to want to come on their own.
They will learn if you move slowly, are gentle, and carry good treats!