How do I configure and limit the allowlist if multiple endpoints are requested in the Mini Program or the bucket name is uncertain?

When you instantiate the SDK, use ForcePathStyle:true to enable the suffix style. If you make a suffix style request in a URL formatted as https://cos-ap-beijing.myqcloud.com/<BucketName-APPID>/<Key>, the bucket name /<BucketName-APPID> will also be added to the signature calculation.

How do I save an image in a Mini Program to my device?

First, obtain the image URL using cos.getObjectUrl. Then, call wx.downloadFile to download the image to obtain the temporary path. When the Save Image button appears, click the button to call wx.saveImageToPhotosAlbum to save the image to your album.