Change the case of labels | TrackAsia GL JS Docs

Use the upcase and downcase expressions to change the case of labels.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Change the case of labels</title>
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
<script src="https://unpkg.com/trackasia-gl@1.0.5/dist/trackasia-gl.js"></script>
<link href="https://unpkg.com/trackasia-gl@1.0.5/dist/trackasia-gl.css" rel="stylesheet" />
<style>
	body { margin: 0; padding: 0; }
	#map { position: absolute; top: 0; bottom: 0; width: 100%; }
</style>
</head>
<body>
<div id="map"></div>
<script>
var map = new trackasiagl.Map({
container: 'map', // container id
style: 'https://maps.track-asia.com/styles/v1/streets.json?key=public_key', // stylesheet location
center: {"lat":10.762622,"lng":106.660172}, // starting position
zoom: 12 // starting zoom
});
 
map.on('load', function () {
// data from opendata.cityofboise.org/
map.addSource('off-leash-areas', {
'type': 'geojson',
'data': 'https://docs.track-asia.com/assets/boise.geojson'
});
map.addLayer({
'id': 'off-leash-areas',
'type': 'symbol',
'source': 'off-leash-areas',
'layout': {
'icon-image': 'dog-park-11',
'text-field': [
'format',
['upcase', ['get', 'FacilityName']],
{ 'font-scale': 0.8 },
'\n',
{},
['downcase', ['get', 'Comments']],
{ 'font-scale': 0.6 }
],
'text-font': ['Noto Sans Bold'],
'text-offset': [0, 0.6],
'text-anchor': 'top'
}
});
});
</script>
 
</body>
</html>