I do not know his goals but I know several accomplishments. He painted the Mona Lisa, he created an alarm clock that yanked your feet up to wake you up, he invented bicycles, and he created a metal lion to please the king.
Answer:
There's not really any specific way.
Explanation:
Billie Eilish is a very distinctive singer and there is no real exact way to sound like any particular singer. If you really want to sound like someone the best thing to do is just listen to a particular sentence (or lyric) and repeat it over and over again and each time if your heading in the right track you could sound a bit like her. But there is no exact way to do this.