Alpha versions are stable Some of the features are just not fully finished.
You could otherwise use this code locally:
scene.environmentTexture = new BABYLON.CubeTexture(url, scene);
BABYLON.EnvironmentTextureTools.CreateEnvTextureAsync(
scene.environmentTexture as CubeTexture})
.then((buffer: ArrayBuffer) => {
var blob = new Blob([buffer], { type: "octet/stream" });
Tools.Download(blob, "environment.env");
})
.catch((error: any) => {
console.error(error);
alert(error);
});