場所にゆっくり飛ぶ | Mapbox GL JS | ドキュメント

flyOptionsでflyToを使用します。
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>場所にゆっくり飛ぶ</title>
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no">
<link href="https://api.mapbox.com/mapbox-gl-js/v2.14.1/mapbox-gl.css" rel="stylesheet">
<script src="https://api.mapbox.com/mapbox-gl-js/v2.14.1/mapbox-gl.js"></script>
<style>
body { margin: 0; padding: 0; }
#map { position: absolute; top: 0; bottom: 0; width: 100%; }
</style>
</head>
<body>
<style>
#fly {
display: block;
position: relative;
margin: 0px auto;
width: 50%;
height: 40px;
padding: 10px;
border: none;
border-radius: 3px;
font-size: 12px;
text-align: center;
color: #fff;
background: #ee8a65;
}
</style>
<div id="map"></div>
<br>
<button id="fly">Fly</button>
<script>
	// TO MAKE THE MAP APPEAR YOU MUST
	// ADD YOUR ACCESS TOKEN FROM
	// https://account.mapbox.com
	mapboxgl.accessToken = 'YOUR_MAPBOX_ACCESS_TOKEN';
const start = [-74.5, 40];
const end = [74.5, 40];
const map = new mapboxgl.Map({
container: 'map',
style: 'mapbox://styles/mapbox/streets-v11',
center: start,
zoom: 9
});
 
let isAtStart = true;
 
document.getElementById('fly').addEventListener('click', () => {
// depending on whether we're currently at point a or b, aim for
// point a or b
const target = isAtStart ? end : start;
 
// and now we're at the opposite point
isAtStart = !isAtStart;
 
map.flyTo({
// These options control the ending camera position: centered at
// the target, at zoom level 9, and north up.
center: target,
zoom: 9,
bearing: 0,
 
// These options control the flight curve, making it move
// slowly and zoom out almost completely before starting
// to pan.
speed: 0.2, // make the flying slow
curve: 1, // change the speed at which it zooms out
 
// This can be any easing function: it takes a number between
// 0 and 1 and returns another number between 0 and 1.
easing: (t) => t,
 
// this animation is considered essential with respect to prefers-reduced-motion
essential: true
});
});
</script>
 
</body>
</html>