Why did the Portuguese king refuse Fernand Magellan’s offer?

The real discovery of the Pacific Ocean was that Fernand Magellan traveled around the world. Magellan himself, he is known to us as a Portuguese navigator, his years of life (1480-1521). He went down in history as the first person to travel around the world. He himself was born on November 20 in Portugal, belonged to a noble family, after receiving a proper education, he decided to enter the navy. After a certain time, the Portuguese king refused Magellan’s offer to travel around the world, since he believed that the earth was flat, and Magellan could and wanted to refute this delusion by traveling the world.